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The objective of this experiment was to evaluate a glycogenic feed additive in terms of performance and response in blood metabolites in weaned horses. Twenty weaned horses of the Unidad de Policía Montada Metropolitana del Ministerio de Seguridad Pública del Gobierno de la Ciudad de México, México, were randomly assigned to two treatment groups: control or an oral dose of the glycogenic additive (10 g/d). The additive was based on propylene glycol and Na/Ca propionate and was supplied for 30 days. Data were tested for normality and initial weight was used as a covariate for analyzing the average daily gain (ADG). The ADG was negatively affected (P < 0.01) by the glycogenic compound (0.468 vs. 0.517 kg), while there were no significant differences (P > 0.10) in blood glucose, globulins, total glucose, triglycerides, cholesterol, creatinine or urea in horses from either treatment group. It was concluded that the glucogenic additive, based on propylene glycol and Na/Ca propionate, negatively affected the performance of the horses. Therefore, administration of the additive is not recommended in weaned horses. [ABSTRACT FROM AUTHOR]

Turkey plays an important role in the international trade of apricots as it has the largest production rate in the world. Since the sulphurisation process is allowed to be used for different products, the effect of residual sulphur and its compounds (which can be found in products as pesticide residues or additive residues) on the positive detection of carbon disulphide (CS2) still creates a big challenge in international trade. Therefore, the main objective of the present study was to investigate the effects of residues of sulphur or sulphur compounds on dithiocarbamate analysis methods based on CS2 measurement. In this study, apricots were chosen since they contain sulphur residues as a result of the sulphurisation process. Sulphur dioxide and dithiocarbamate analyses were conducted on dried apricots prepared with the sulphurisation process (SA) and without the sulphurisation process (NSA); analysis was by two different accredited laboratories. No of pesticide was applied to either SA or NSA samples. Although some of the NSA samples had

VevoVitall® is a feed additive consisting of benzoic acid. It is currently authorised as a zootechnical additive for weaned piglets and pigs for fattening. This opinion concerns the renewal of the authorisation of benzoic acid as a zootechnical additive in feed. In 2005 and 2017, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) adopted two opinions on the safety and efficacy of VevoVitall® as a feed additive for weaned piglets and pigs for fattening, respectively. The applicant has provided data demonstrating that the additive currently in the market complies with the conditions of authorisation. Furthermore, according to the information provided in the technical dossier, no new evidence has been identified that would make the FEEDAP Panel reconsidering the previous conclusions on the safety of the additive. The Panel confirms that the additive is safe at the maximum authorised concentrations of 5,000 and 10,000 mg/kg feed for weaned piglets and pigs for fattening, respectively; a margin of safety cannot be determined for weaned piglets while a margin of safety of less than 1.5 is established for pigs for fattening. The use of VevoVitall® in feeds for weaned piglets and pigs for fattening at the maximum authorised concentrations does not pose any safety concern for consumers and the environment. The use of VevoVitall® does not pose a risk by inhalation to users and is not a skin sensitiser. The new available data confirm that the additive is a skin irritant and a severe eye irritant. A recommendation concerning the potential toluene residues in the additive has been posted. [ABSTRACT FROM AUTHOR]

In this work, a novel analytical method was established for simultaneous determination of E-fluoxastrobin and Z-fluoxastrobin in vegetables and fruits. After extracted by acetonitrile, the samples were cleansing with dispersive solid liquid extraction (d-SLE) process, and analyzed by ultra high performance liquid chromatography coupled to diode array detection (UHPLC-DAD). The effectiveness of the optimized method was validated by determining the linearity (R 2 > 0.99), sensitivity (limits of quantification of 30 μg/kg), recovery (71.3–113.2%), and precision (relative standard deviations, RSDs ≤ 13.9%) in eight vegetable and fruit samples. The results suggested that this method was simple, reliable, and feasible to determine the residues of E-fluoxastrobin and Z-fluoxastrobin in vegetable and fruit samples, which could be further applied to 160 various vegetable and fruit samples. [ABSTRACT FROM AUTHOR]

The central Asian Republic of Tajikistan has been an area of extensive historical agricultural pesticide use as well as large scale burials of banned chlorinated insecticides. The current investigation was a four year study of legacy organochlorine pesticides in surface soil and raw foods in four rural areas of Tajikistan. Study areas included the pesticide burial sites of Konibodom and Vakhsh, and family farms of Garm and Chimbuloq villages. These areas were selected to represent a diversity of pesticide disposal histories and to allow assessment of local pesticide contamination in Tajikistan. Each site was visited multiple times and over 500 samples of surface soil and raw foods were collected and analyzed for twenty legacy organochlorine pesticides. Various local food products were sampled to represent the range of raw foods potentially containing residues of banned pesticides, including dairy products, meat, edible plant and cotton seed products. The pesticide analytes included DDTs (DDT, DDD, DDE), lindane isomers (α, ß, γ, δ BHC), endosulfan isomers (endosulfan I, II, sulfate), other cyclodienes (aldrin, a and chlordanes, dieldrin, endrin, endrin aldehyde and ketone, heptachlor, heptachlor epoxide), and methoxychlor. Pesticide analytes were selected based on availability of commercial standards and known or suspected historical pesticide use and burial. Pesticide contamination was highest in soil and generally low in meat, dairy, and plant products. DDT was consistently the highest measured individual pesticide at each of the four sampling areas, along with BHC isomers and endosulfan II. Soil concentrations of pesticides were extremely heterogeneous at the Vakhsh and Konibodam disposal sites with many soil samples greater than 10 ppm. In contrast, samples from farms in Chimbuloq and Garm had low concentrations of pesticides. Pesticide contamination in raw foods was generally low, indicating minimal transfer from the pesticide sites into local food chains. [ABSTRACT FROM AUTHOR]

Research on the storage stability of antibiotic residues in milk is important for method development or validation, milk quality control and risk assessment during screening, confirmation, qualitative or quantitative analysis. This study was conducted using UPLC-MS/MS to determine the stability of six quinolones - ciprofloxacin (CIP), danofloxacin (DAN), enrofloxacin (ENR), sarafloxacin (SAR), difloxacin (DIF) and flumequine (FLU) - in raw milk stored under various conditions to investigate if quinolones degrade during storage of milk, and finally to determine optimal storage conditions for analysis and scientific risk assessment of quinolone residues in raw milk. The storage conditions included different temperatures and durations (4°C for 4, 8, 24 and 48 h; -20°C for 1, 7 and 30 days; -80°C for 1, 7 and 30 days), thawing temperatures (25, 40 and 60°C), freeze-thaw cycles (1-5), and the addition of different preservatives (sodium thiocyanate, sodium azide, potassium dichromate, bronopol and methanal). Most quinolones exhibited high stability at 4°C for up to 24 h, but began to degrade after 48 h. In addition, no degradation of quinolones was seen whenmilk samples were stored at -20°C for up to 7 days; however, 30 days of storage at -20°C resulted in a small amount of degradation (about 30%). Similar results were seen when samples were stored at -80°C. Moreover, no losses were observed when frozen milk samples were thawed at 25, 40 or 60°C. All the quinolones of interest, except sarafloxacin, were stable when milk samples were thawed at 40°C once and three times, but unstable after five freeze-thaw cycles. Preservatives affected the stability of quinolones, but the effects differed depending on the preservative and quinolone. The results of this study indicate optimum storage protocols for milk samples, so that residue levels reflect those at the time of initial sample analysis, and should improve surveillance programmes for quinolones in raw milk. [ABSTRACT FROM AUTHOR]

A ranking system for veterinary medicinal products and coccidiostat feed additives has been developed as a tool to be applied in a risk-based approach to the residue testing programme for foods of animal origin in the Irish National Residue Control Plan (NRCP). Three characteristics of substances that may occur as residues in food are included in the developed risk ranking system: Potency, as measured by the acceptable daily intake assigned by the European Medicines Agency Committee for Medicinal Products for Veterinary Use, to each substance; Usage, as measured by the three factors of Number of Doses, use on Individual animals or for Group treatment, and Withdrawal Period; and Residue Occurrence, as measured by the number of Non-Compliant Samples in the NRCP. For both Number of Doses and Non-Compliant Samples, data for the 5-year period 2008-12 have been used. The risk ranking system for substances was developed for beef cattle, sheep and goats, pigs, chickens and dairy cattle using a scoring system applied to the various parameters described above to give an overall score based on the following equation: Potency × Usage (Number of Doses + Individual/Group Use + Withdrawal Period) × Residue Occurrence. Applying this risk ranking system, the following substances are ranked very highly: antimicrobials such as amoxicillin (for all species except pigs), marbofloxacillin (for beef cattle), oxytetracycline (for all species except chickens), sulfadiazine with trimethoprim (for pigs and chickens) and tilmicosin (for chickens); antiparasitic drugs, such as the benzimidazoles triclabendazole (for beef and dairy cattle), fenbendazole/oxfendazole (for sheep/goats and dairy cattle) and albendazole (for dairy cattle), the avermectin ivermectin (for beef cattle), and anti-fluke drugs closantel and rafoxanide (for sheep/goats); the anticoccidials monensin, narasin, nicarbazin and toltrazuril (for chickens). The risk ranking system described is a relatively simple system designed to provide a reliable basis for selecting the veterinary medicinal products and coccidiostat feed additives that might be prioritised for residue testing. [ABSTRACT FROM AUTHOR]

Aim: This study was aimed to evaluate some biochemical, hormonal, hematological, and histopathological changes in Nile tilapia, Oreochromis niloticus, after acute exposure to nonylphenol (NP). In addition to detection of NP residues in the fish, muscle tissues for human health concern. Materials and Methods: A total of 90 apparently healthy Nile tilapia, O. niloticus, were randomly divided into three equal groups; each containing 30 fish (three replicates). Groups 1 and 2 kept as a control and solvent control (acetone), respectively, and Group 3 exposed to NP at a dose level of 500 µg/L water for 7 successive days. Blood and tissue samples were collected 2 times randomly from each group after 7 days from fish exposure to NP and 10 days from exposure stopping. Results: Fish exposed to NP Group 3 showed anorexia, sluggish movement, erythema of the skin, areas of scales loss, and hemorrhagic ulcers in some areas of body region leading to exposing the viscera. Biochemical results revealed a significant increase in serum total proteins and globulins levels, a highly significant increase in serum alanine aminotransferase and aspartate aminotransferase activities, triglycerides, cholesterol, and creatinine levels, insignificant increase in serum uric acid level, and a highly significant decrease in serum testosterone and estradiol-ß17 levels in Group 3 in compare with the control group. Histopathological finding confirms these results. While hematological results of the same group revealed a significant increase in red blood cells count and packed cell volume value, insignificant increase in hemoglobin concentration, leukopenia, lymphopenia, and monocytopenia in compared with the control group. All of these changes appeared after 7 days from fish exposure to NP. Most of these alterations returned toward the normal level after 10 days from stopping exposure to NP. NP residues detected in fish muscle tissues of Group 3 during exposure and after stopping exposure to it. Conclusion: It is concluded that NP is a toxic pollutant and has an adverse effect on fish health and reproduction as well as accumulates in fish muscle tissues which may cause human health hazard. [ABSTRACT FROM AUTHOR]

The use of medium–high-resolution mass spectrometers (M–HRMS) provides many advantages in multi-residue analysis. A comparison between two mass spectrometers, medium-resolution (MRMS) time-of-flight (TOF) and high-resolution (HRMS) Orbitrap, has been carried out for the analysis of toxic compounds in animal feed. More than 300 compounds belonging to several classes of veterinary drugs (VDs) and pesticides have been determined in different animal feed samples using a generic extraction method. The use of a clean-up procedure has been evaluated in both instruments, and several validation parameters have been established, such as the matrix effect, linearity, recovery and sensitivity. Finally, both instruments have been used during the analysis of 18 different feed samples (including chicken, hen, rabbit and horse). Some VDs (sulfadiazine, trimethoprim, robenidine and monensin sodium) and one pesticide (chlorpyrifos) have been identified. In general, better results were obtained using the Orbitrap, such as sensitivity (1–12.5 µg kg−1) and recovery values (60–125%). Moreover, this analyser had several software tools, which reduced the time for data processing and were easy to use, performing quick screening for more than 450 compounds in less than 5 min. However, some disadvantages such as the high cost and a decrease in the number of detected compounds at low concentrations must be taken into account. [ABSTRACT FROM PUBLISHER]

In accordance with Article 6 of Regulation (EC) No 396/2005, both France, hereafter referred to as the evaluating Member State (EMS-FR), and the Netherlands, hereafter referred to as the evaluating Member State (EMS-NL) received an application from ISK Biosciences Europe N.V. to modify the existing maximum residue levels (MRLs) for the active substance flonicamid in peas without pods, cotton seeds and rye (EMS-FR) and peppers, Brussels sprouts, barley and oat (EMS-NL). France and the Netherlands drafted an evaluation report in accordance with Article 8 of Regulation (EC) No 396/2005 which was submitted to the European Commission and forwarded to EFSA. According to EFSA the data are sufficient to derive MRL proposals of 0.3 mg/kg for peppers (indoor uses), 0.6 mg/kg for Brussels sprouts, 0.7 mg/kg for peas without pods, 0.2 mg/kg for cotton seeds, 0.4 mg/kg for barley and oat. The extrapolation to rye of the current MRL of 2 mg/kg set on wheat in the EU legislation and recommended during the Article 12 review of the existing MRLs is confirmed. Sufficient data were not provided to support the outdoor use of flonicamid on peppers. Adequate analytical methods are available to control the residues of flonicamid and its metabolites TFNG and TFNA in the crops under consideration. Based on the risk assessment results, EFSA concludes thatthe proposed uses of flonicamid on the crops under consideration will not result in a consumer exposure exceeding the toxicological reference values and therefore are unlikely to pose a consumer health risk. [ABSTRACT FROM AUTHOR]

In accordance with Article 6 of Regulation (EC) No 396/2005, the evaluating Member State (EMS), United Kingdom, received an application from Bayer CropScience S.A.S. to modify the existing maximum residue level (MRL) for the active substance prothioconazole in shallots. In order to accommodate for the intended use of prothioconazole, United Kingdom proposed to set the MRL at the limit of quantification (LOQ) of 0.05 mg/kg. According to EFSA the data are sufficient to derive a MRL proposal of 0.05 mg/kg (LOQ) for the intended use on shallots in northern Europe. Adequate analytical enforcement methods are available to control the residues of prothioconazole-desthio in the commodity under consideration. Based on the risk assessment results, EFSA concludes that the proposed use of prothioconazole on shallots will not result in a consumer exposure exceeding the toxicological reference values and therefore is unlikely to pose a consumer health risk. However, the consumer risk assessment should be regarded as provisional since the possible contribution of the triazole derivative metabolites (TDMs) in the consumer risk assessment was not taken into consideration. [ABSTRACT FROM AUTHOR]

The occurrence of residues of DDT and its metabolites was monitored in 196 cow milk samples of various pasteurized commercial types collected from the Greek market. Residue levels were determined by GC-MS analysis. In 97.4% of the samples at least one DDT isomer or one of the DDT metabolites was detected, in levels not exceeding the maximum permitted residue level by the EU. Hazard Index for both carcinogenic and non-carcinogenic effects was estimated under two assumptions: a) using DDT concentrations from positive samples and b) imputing LOD/2 as an arbitrary concentration for negative samples. No statistically significant differences in detected or summed residue (p > 0.05) concentrations between different milk types were observed, with the exception of specific metabolites of DDT in some milk types. Exposure assessment scenarios were developed for children aged 1, 3, 5, 7 and 12 years old based on estimated body weights and daily milk consumption. Hazard Indices for non-carcinogenic effects were below 0.109 covering also carcinogenic effects according to WHO approach. The cancer risk values for carcinogenic effects according to the US EPA Cancer Benchmark Concentration approach, ranged from 0.4 to 18. For both effects the highest values were calculated for the 1- to 3-year-old age groups. [ABSTRACT FROM AUTHOR]

The experiment was conducted on 2640 slow-growing (NL-JA-757) broiler chicks divided into three groups with eight replicates of 110 chicks each for period of 49 days. The control group was fed diets without any color additive, while experimental groups A and B were fed diets containing commercial color additive (0.05%) and sea buckthorn fruit residue 5% of feed respectively. Diets BR1 (starter) were fed from day 1 to 21; BR2 (grower) were fed from day 22 to 35, and BR3 (finisher) were fed from day 36 to 49. The chicks were weighed on days 21, 35 and 49. The final mean live weight of the birds (males and females) appeared lower in group B with sea buckthorn in comparison with the control group (1848.1 vs.1875.5g) and group A (1882.5g). Feed conversion at 49 days was poorer in group B (2182.6 g/kg) in comparison with group A (2102.4g/kg) and non-significantly poorer than the control group (2163.7 g/kg). Skin color was assessed by the DSM Broiler Fan expressed on a 101-110 scale. The skin of the birds was more yellowish in group A (104.4) in comparison with group B (103.0) and the control group (102.5). Neither the health of the birds nor their mortality was affected by the diets. [ABSTRACT FROM AUTHOR]

This study was conducted to determine the effects frying, boiling and freezing processes on the levels of sulfachlorpyridazine (SCP) and trimethoprim (TMP) in broiler chest meat and liver. Male broiler chicks were assigned to two groups as control and treatment groups. Animals were fed on commercial diet not containing SCP and TMP for 35 days. At 30th day, experimental group received suspensions of SCP-TMP mixture (30 mg/kg SCP and 6 mg/kg TMP) via craw by gavage once daily for 5 days. At the end of 35th day, the chickens were sacrified and right chest tissue and the liver were taken out. A portion of the tissues were stored in -20°C freezer for 30 and 45 days. After sacrifiying, the raw tissues were exposed to frying and boiling processes. SCP and TMP analysis of tissues were performed by HPLC-DAD detector and reverse phase column. In conclusion, it has been determined that boiled and grilled processes caused a reduction of SCP and TMP residues at different rates in broiler tissues; while storing in the deep freezer did not cause a significant change on SCP and TMP residues. [ABSTRACT FROM AUTHOR]

In 2008, the discovery of elevated levels of dioxins and PCBs in a porcine fat sample taken as part of the national residues monitoring programme led to the detection of a major feed contamination incidence in the Republic of Ireland. To estimate additional exposure to dioxins and PCBs due to the contamination incident, all data associated with the contamination incident were collected and reviewed. An exposure model was devised that took into account the proportion of contaminated product reaching the final consumer during the contamination incident window and which utilised all additional information that became available after the incident occurred. Exposure estimates derived for both dioxins and PCBs showed that the body burden of the general population remained largely unaffected by the contamination incident and only approximately 10% were exposed to elevated levels of dioxins and PCBs. Whilst this proportion of the population experienced quite a significant additional load to the existing body burden, the estimated exposure values do not suggest that these would be associated with adverse health effects, based on current knowledge. The exposure period was also limited in time to approximately 3 months, following the recall of contaminated meat immediately on detection of the contamination. [ABSTRACT FROM AUTHOR]

Due to strict regulatory requirements for pesticide residue analysis, only the results of residue analysis with acceptable quality should be reported. As a consequence proper validation of the measurement method is required. In this context, accuracy, precision, specificity, limit of determination (LOQ), matrix effect, linearity, uncertainty calculation and ruggedness become increasingly important. This paper reports a description of the validation parameters of a fast method for the determination of five phenoxy acid herbicides (2,4-D, MCPA, MCPP, haloxyfop and fluazifop) in food crops. The recoveries were performed in the concentration range from 0.05 to 0.5 mg kg–1for apples, pears, carrots and celeriac with five replicates at each level. The mean recoveries ranged from 70% to 95% for all crops. The precision of the method expressed as a relative standard deviation (RSD%) was found to be in the range 3–14%. For all herbicides, the linearity response of the detector was tested by correlation coefficients (r2 > 0.99) in the concentration range from 0.05 to 0.5 mg kg–1. The LOQ was determined as the lowest spiked level meeting the requirement of accuracy (70–120%) and precision (RSD% < 20% according to European Union guidelines. The uncertainty and robustness were calculated. On the basis of the results, the method can be considered fast, simple and robust and is suitable to be applied to the analysis of studied herbicides in routine testing laboratories. [ABSTRACT FROM AUTHOR]

Deccox® contains decoquinate as the active substance for prevention of coccidiosis in poultry. The applicant requested a reduction in the withdrawal time from three days to zero days and the introduction of maximum residue limits (MRLs) for liver (1.0 mg/kg), kidney (0.8 mg/kg), muscle (0.5 mg/kg) and skin/fat (1.0 mg/kg). Decoquinate is not genotoxic and is not carcinogenic. The lowest no observed effect level (NOEL) was 15 mg/kg bw per day, observed in a 12-week oral toxicity study in dogs. The acceptable daily intake (ADI) of decoquinate (already established by the FEEDAP Panel in 2003 and since confirmed) is 0.075 mg/kg body weight (bw), based on the above NOEL, applying an uncertainty factor of 200. On the basis of new metabolism/residue studies in chicken and rat, major metabolites appear to be dissimilar in these two species. Nevertheless, the assessment of consumer safety refers to the ADI of decoquinate, considering the limited exposure of consumers to metabolites from chicken tissues. Decoquinate is the marker residue. A conservative estimate of consumer exposure, based on total residues measured after two and six hours withdrawal, indicates that it would be about 2 % of the ADI. Since a withdrawal period of two and six hours corresponds to a zero withdrawal time under practical husbandry conditions, a zero days withdrawal time does not compromise consumer safety. The new residue data submitted confirm that no MRLs are considered necessary. [ABSTRACT FROM AUTHOR]

According to Article 12 of Regulation (EC) No 396/2005, the European Food Safety Authority (EFSA) has reviewed the Maximum Residue Levels (MRLs) currently established at European level for the pesticide active substance propargite. Although this active substance is no longer authorised within the European Union, MRLs were established by the Codex Alimentarius Commission (CXLs). Based on the assessment of the available data, EFSA assessed the CXLs. CXLs were found not to be adequately supported by data and a consumer risk assessment could not be carried out. Hence, further consideration by risk managers is needed. [ABSTRACT FROM AUTHOR]

The residue depletion profile of sulfachlorpyrazine was studied in healthy broilers after oral administration of Sulfatyf®, given at a dose of 50 mg sulfachlorpyrazine (SCP) per kg body weight once daily for 3 consecutive days. Twenty-five medicated broilers were slaughtered on the 5th, 10th, 14th and 16th day of post-medication, and muscle, fat with skin, liver and kidney tissues were sampled and analysed using an high-performance liquid chromatography (HPLC) method with satisfactory recovery (74.5% ± 2.9%) and specificity. The estimated values of LOD and LOQ were 18.40 and 55.70 ng ml−1, respectively. On the 5th and 10th day of post-medication, the concentrations of SCP residue in all samples examined were higher than the corresponding MRLs established by the European Union and the highest SCP concentrations were measured in muscle. A maximum withdrawal time of 14 days was calculated to ensure consumer safety. [ABSTRACT FROM PUBLISHER]

Recent legislation has addressed the unavoidable carry-over of coccidiostats and histomonostats in feed, which may lead to the presence of residues of these compounds in eggs. In this study, laying hens received cross-contaminated feed at a ratio of 2.5%, 5% and 10% of the therapeutic dose of monensin and lasalocid for broilers. The eggs were collected during the treatment and depletion period and were analysed using liquid chromatography-tandem mass spectrometry. The different egg matrices were separated and analysed during the plateau phase. High lasalocid concentrations, which exceeded the maximum residue level, and low monensin concentrations were found in whole egg. Plateau levels were reached at days 7–9 for lasalocid and at days 3–5 for monensin. For lasalocid, the highest concentrations were measured in egg yolk; residue concentrations in egg white were very low. [ABSTRACT FROM AUTHOR]

The results of thermolysis of vacuum resid of West Siberian oil are reported. A mathematical model has been built and kinematic relationships of the process of production of an oil-caking additive, namely the thermolysis residue, have been described. It is shown that conversion of the feedstock into volatile products occurs via the quasi-linear mechanism of first-order reactions, whereas conversion into carbenes and carboids (б-fraction) occurs via the autocatalytic mechanism of self-accelerating radical processes. In order to support the theory of autocatalytic mechanism, the effect of addition of various quantities of carbine and carboid concentrate to the feedstock composites on the polycondensation reaction rate was studied. It was observed that the group composition of the thermolysis residue changes nonadditively, which attests to autocatalytic action of carbines and carboids added to the thermolysis feedstock. [ABSTRACT FROM AUTHOR]

In this study, residual concentrations of chlorpyrifos (CPF) were determined in feed (40) and fodder (25) samples collected from various locations of Tarai region of Uttarakhand. For extracting residues, liquid–liquid partition followed by alumina column clean up was used and the detection and quantification of residues was undertaken with the help of high-performance liquid chromatography using C18 column and diode array detector at 220 nm. Of the total 40 feed samples analyzed, 7 (17.5%) samples were found positive for CPF with the mean residual concentration of 0.058 µg g−1; while out of 25 fodder samples, CPF residues were detected in a single (4%) sample with residual concentration of 0.39 µg g−1. However, none of the feed or fodder samples contained CPF residues above the prescribed limit. [ABSTRACT FROM PUBLISHER]

The feed drug additive carbadox is a suspected carcinogen and mutagen. To monitor effectively residues of carbadox in the edible tissues of food-producing animals, an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) to detect quinoxaline-2-carboxylic acid, the marker residue of carbadox, was developed. Several haptens were synthesised and conjugated to the carrier protein. Nine female New Zealand white rabbits were immunised with the immunising conjugates to produce polyclonal antibodies according to the designed schemes of immunisation. The highly specific antibody that was very sensitive to N-butylquinoxaline-2-carboxamide with an IC50 value of 7.75 µg l−1 was selected for the development of an ic-ELISA. The standard curves based on the N-butylquinoxaline-2-carboxamide matrix calibration ranged from 0.2 to 51.2 µg l−1. The decision limit and detection capability of the ic-ELISA were 0.60 and 0.83 µg kg−1 for liver and 0.68 and 0.79 µg kg−1 for muscle of swine, respectively. The recoveries were 57–108% with coefficients of variation of less than 20% when the quinoxaline-2-carboxylic acid was spiked into liver and muscle with the concentrations of 1.0–20.0 µg kg−1. Excellent correlations between the results of the ic-ELISA and an HPLC method (r = 0.9956 − 0.9969) were observed for incurred tissues. These results suggest that the ic-ELISA is a sensitive, accurate and low-cost method that would be a useful tool for screening residues of carbadox in the edible tissues of food-producing animals. [ABSTRACT FROM AUTHOR]

Abstract: Bioenergy production from crops and agricultural residues has a greenhouse gas mitigation potential. However, there is considerable debate about the size of this potential. This is partly due to difficulties in estimating the feedstock resource base accurately and with good spatial resolution. Here we provide two techniques for spatially estimating crop-based bioenergy feedstocks in Australia using regional agricultural statistics and national land use maps. The approach accommodates temporal variability by estimating ranges of feedstock availability and the shifting nature of zones of the highest spatial concentration of feedstocks. The techniques are applicable to biomass production from forestry, agricultural residues or oilseeds, all of which have been proposed as biofuel feedstocks. [Copyright &y& Elsevier]

An experiment was carried out to determine melamine residual levels in eggs by feeding laying hens 200 or 1,000 mg of rnelamine/kg of diet. Each diet was offered in 3 replicate cages (10 laying hens/ cage) from d 1 to 29, followed by a 9-d feeding of a withdrawal diet that contained no melamine. Two eggs were collected from each replicate cage each day for the determination of residual melamine levels after 1 d of feeding. The feeding of melamine resulted in a fast accumulation of melamine in eggs within 3 to 4 d, then maintained 2.00 to 3.88 mg/kg for 200 mg of melamine/ kg of diet and 11.09 to 16.46 mg/kg for 1,000 mg of melamine/kg of diet. A withdrawal period of 4.0 ci for 1,000 mg of melamine/kg of diet was required based on tolerance values established by the World Health Organization and no withdrawal period was required for 200 mg of melamine/kg of diet. [ABSTRACT FROM AUTHOR]

Abstract: High-performance liquid chromatographic method with diode-array detection (HPLC–DAD) was optimised and validated for determination of tetracyclines (TCs) residue in chicken meat and liver through evaluating each step of various methods. The principle steps involved ultrasonic-assisted extraction of TCs from chicken samples by 2ml of 20% trichloroacetic acid and citrate buffer (pH 4) which gave a clearer supernatant and high recovery, followed by centrifugation and purification on SPE (Strata C18-E cartridge) using 10ml of 0.01M methanolic oxalic acid for TCs elution. Separation was on reversed-phase column (Nuclosil 100 C18, 25cm×4.6mm ID, 5μ) by multisteps gradient elution which provided a better chromatographic peak resolution and the late eluting peaks were as sharp as those eluting earlier. Monitoring was at 351nm which gave a higher detector response factor. Validity study of the method revealed that all obtained calibration curves showed good linearity (r 2 >0.999) over the range of 50–5000ng. Sensitivity was found to be 1.44, 1.90, 0.95 and 1.23ng for OTC, TC, CTC and DC, respectively. Accuracy was in the range of 71.88–92.44.3% and 68.88–84.84% for meat and liver, respectively. Precision was lower than 10% in all cases indicating that the method can be used as a validated method. Limit of detection (LOD) was found to be 4.4, 5, 13 and 10ng for OTC, TC, CTC and DC, respectively. The corresponding values of limit of quantitation (LOQ) were 10, 13, 27 and 22ng. [ABSTRACT FROM AUTHOR]

Residue levels of seven organophosphorus pesticides (OPPs), widely used as dairy cattle ectoparasiticides or in crops used for animal feed, were determined in raw milk and infant formulas. A total of 312 samples were collected (70 from infant formulas and 242 from raw milk) biweekly during a 24-month period. Pesticides were extracted by means of a solid phase system into acetone. An extract aliquot of acetone was injected into a gas chromatograph (GC) with a nitrogen-phosphorus detector. Recoveries of pesticides spiked in milk samples were 62.2 - 97.2 %. The frequency of total samples containing detectable levels of OPP residues was 6.73 % in total milk and 8.67 % in raw milk. The highest percentage incidence measured was for dichlorvos (5.78 %), followed by coumaphos (2.06 %), and parathion methyl (0.83 %). The range of positive results was calculated to be between 0.005 and 0.220 mg kg- 1. No residue was detected in the final product (infant formulas), so any risk to consumer health, especially to children's health, would be limited. [ABSTRACT FROM AUTHOR]

In the last two years melamine has become matter of great interest. This substance has been abused during food and feed adulteration by increasing the content of nitrogen compounds in these products. Individually, melamine is not toxic. When combined melamine and cyanuric acid in the bloodstream, they accumulate in the kidneys and form very large insoluble crystals (melamine- cyanurate), which in turn can lead to renal failure and ultimately, death. In this paper we present analytical method for melamine in different food matrices by gas chromatography with tandem mass spectrometry. [ABSTRACT FROM AUTHOR]

Abstract: Defective coffee press cake, a residue from coffee oil biodiesel production, was evaluated as an adsorbent for removal of basic dyes (methylene blue – MB) from aqueous solutions. The adsorbent was prepared by microwave treatment, providing a significant reduction in processing time coupled to an increase in adsorption capacity in comparison to conventional carbonization in a muffle furnace. Batch adsorption tests were performed at 25°C and the effects of particle size, contact time, adsorbent dosage and initial solution pH were investigated. Adsorption kinetics was better described by a second-order model. The experimental adsorption equilibrium data were fitted to Langmuir, Freundlich and Tempkin adsorption models, with Langmuir providing the best fit. The results presented in this study show that microwave activation presents great potential as an alternative method in the production of adsorbents. [Copyright &y& Elsevier]

Abstract: An ELISA was developed for routine examination for extensive monitoring and screening programs for the residues of salbutamol in swine serum, animal feed, meat, and meat-related products destined for human consumption in Taiwan. Objectives of the study were to investigate the use of a new immunoassay for the detection of salbutamol residues in swine meat and animal feed samples, and to compare with a commercial kit in field test screens. A fast, simple and reliable sample preparation method for the determination of salbutamol was established. Field trials with 222 swine meat and 120 animal feed samples that were taken from local meat markets, auction markets and feed mills. The application and the results of two ELISA kits (a homemade and a commercial kit) for the screening of salbutamol were presented. Adopting 2μgkg−1 salbutamol as a cut-off value for swine meat, the commercial β-agonist ELISA had a sensitivity of 85.3% and a specificity of 95.2% versus GC–MS at a cut-off of 2μgkg−1. The homemade salbutamol ELISA had a sensitivity of 100% and a specificity of 90.9% and gave no false-negative rate results. Furthermore, adopting 20μgkg−1 salbutamol as a cut-off value for animal feed, both the commercial and homemade ELISA showed 100% sensitivity and 100% specificity of the assays. In conclusion, a sensitive, specific salbutamol polyclonal antibody-based ELISA has been developed that could serve as a rapid screening assay, and the detection of positive samples at the place of sampling can result in more effective control of the illegal use of β-agonists. [Copyright &y& Elsevier]

A method for the simultaneous determination of flumequine, oxolinic acid, sarafloxacin, danofloxacin, enrofloxacin, and ciprofloxacin in tilapia (Orechromis niloticus) fillet, using high-performance liquid chromatography with fluorescence detection (HPLC-FLD) is presented. The quinolones were extracted from the food matrix with a solution of 10% trichloroacetic acid and methanol (80:20 v/v). Clean-up of the extract was performed using polymeric solid-phase extraction cartridges. Identification of the quinolones was confirmed by liquid chromatography-tandem mass spectrometry. The HPLC-FLD method was validated in-house and the following analytical parameters were obtained: linearity higher than 0.99 for all the quinolones; intra- and inter-assay precisions were lower than 3.5% and 10.9%, respectively; and recoveries ranged from 73% to 110%. The limit of quantification was below the maximum residue limit established by the Joint Expert Committee on Food Additives (JECFA), which indicates that the method is appropriate for the determination of quinolones in fish fillet. [ABSTRACT FROM AUTHOR]

Total of 500 samples from triceps, gluteal and diaphragm muscles, kidney, and liver, were obtained randomly from beef carcasses of a slaughterhouse in Tabriz. We measured oxytetracycline, tetracycline, and chlortetracycline (TCs) residues by high performance liquid chromatography (HPLC) method. Seventy four percent of samples (380 samples) had detectable TCs residues. The mean amounts of oxytetracycline, tetracycline, and chlortetracycline residues in all samples were 52.2, 33.8, and 125.2 μg/kg, respectively. The mean amounts of total residues of TCs in all meat samples, triceps, gluteal and diaphragm muscles, kidney, and liver were 131.0, 163.1, 63.4, 66.7, 408.1, and 254.9 μg/kg, respectively. Five percent of kidney and liver samples and 21.7% of all samples contained residues more than the maximum residue limits (MRLs) of the World Health Organization (WHO). This study indicates presence of different levels of tetracycline residues in the various edible tissues. Regulatory authorities should ensure proper withdrawal period before slaughtering of the animals. [ABSTRACT FROM AUTHOR]

Abstract: Aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor mediating the adverse effects of dioxins and polycyclic aromatic hydrocarbons (PAHs). In this study, we investigated the genetic-, time-, dose-, species- and tissue-dependent AhR-mediated agonistic/antagonistic activities of three food flavonoids: quercetin, chrysin and genistein. To that end, four stably transfected cell lines were used in cell-based luciferase reporter gene assays: three lines were transformed with the ptKLuc vector harbouring four dioxin-responsive elements (DREs) upstream of the thymidine kinase promoter and the luciferase gene (HepG2-Luc, T-47D-Luc and H4IIE-ULg). The fourth is a patented cell line transformed with a different construct: H4IIE DR-CALUX®. Both H4IIE cells were compared for their genetic construction. Human hepatoma (HepG2-Luc) and human breast tumour (T-47D-Luc) cells were compared for tissue-dependent effects. Rat hepatoma (H4IIE-ULg) and human hepatoma (HepG2-Luc) cells were compared for species-dependent activities. We concluded that quercetin, chrysin and genistein act in a time-, dose-, species- and tissue-specific way. For example, genistein displayed agonistic activities when exposed to rat hepatoma cells during 6h but not after 24h. Flavonoids displayed agonistic/antagonistic activities in human breast tumour cells, depending on the exposure time, while in human hepatoma cells, only antagonistic activities of flavonoids were measured. In addition, we report, in all the cells, a synergy between an isoflavone and two food contaminants; the 2,3,7,8-tetrachlorodibenzo-p-dioxin and 3-methylcholanthrene, a PAH. In rat cells, this synergy occurred when cells were exposed to flavonoids and contaminant for 6h, while it was observed in human cells only after 24h. [Copyright &y& Elsevier]

Abstract: Food safety is a strategic topic entailing not only national public health aspects but also competitiveness in international trade. An important component of any food safety program is the control and monitoring of residues posed by certain substances involved in food production. In turn, a National Residue Control Plan (NRCP) relies on an appropriate laboratory network, not only to generate analytical results, but also more broadly to verify and co-validate the controls built along the food production chain. Therefore laboratories operating under a NRCP should work in close cooperation with inspection bodies, fostering the critical alignment of the whole system with the principles of risk analysis. Beyond producing technically valid results, these laboratories should arguably be able to assist in the prediction and establishment of targets for official control. In pursuit of analytical excellence, the Brazilian government has developed a strategic plan for Official Agricultural Laboratories. Inserted in a national agenda for agricultural risk analysis, the plan has succeeded in raising laboratory budget by approximately 200%, it has started a rigorous program for personnel capacity-building, it has initiated strategic cooperation with international reference centres, and finally, it has completely renewed instrumental resources and rapidly triggered a program aimed at full laboratory compliance with ISO/IEC 17025 requirements. [Copyright &y& Elsevier]

Abstract: Growth-promoting agents are illicitly used during animal rearing processes and the detection of their use is limited by new compounds and dosing practices that limit the efficiency of current testing which is based on residue analysis by liquid chromatography–tandem mass spectrometry (LC–MS/MS) and gas chromatography–mass spectrometry (GC–MS) methodology. An alternative approach is to use indirect biological evidence as a screening tool to identify growth-promoter treated animals thus improving the effectiveness of residue testing through the targeted sampling of these animals. Sex hormone-binding globulin (SHBG) is a glycoprotein which binds and controls the levels of sex-hormones within the circulation. Using a biosensor assay based on measurement of binding to an immobilised 1α-dihydrotestosterone (1α-DHT) derivative, reduced SHBG binding capacities were detected in growth-promoter treated animals. During the course of a veal treatment regime based on repeated oestradiol benzoate, nortestosterone decanoate and dexamethasone administrations, treated male and female calves were shown to have significantly lower SHBG capacities. To assess the effectiveness of using SHBG binding capacities as a biomarker of treatment and to investigate the role of individual growth-promoter components to the SHBG capacity lowering effects, adult heifer animals were subjected to repeated doses of nortestosterone decanoate. These animals also demonstrated a reduction in SHBG capacity levels at Day 39 of the study, in contrast to oestradiol benzoate treated adult steers who were found to have unaltered levels. These findings suggest that the measurement of SHBG binding capacities using a biosensor assay has potential in the identification of illegally treated animals, particularly those exposed to androgens. [Copyright &y& Elsevier]

Abstract: Liquid chromatographic methods are presented for the quantitative and confirmatory determination of crystal violet (CV; also known as gentian violet), leucocrystal violet (LCV), brilliant green (BG), and leucobrilliant green (LBG) in catfish. LCV and LBG were oxidized to the chromic CV and BG by reaction with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone, and residues were measured as the combined CV±LCV and BG±LBG. These methods are extensions of published methods for malachite green (MG) analysis to allow simultaneous determination of MG, CV, and BG. Residues were extracted from muscle with ammonium acetate buffer and acetonitrile, and extracts cleaned up using dichloromethane partitioning and solid-phase extraction. Extracts were analyzed by liquid chromatography with visible detection (LC-VIS). The method was validated for catfish fortified with LCV over the range 0.25–10ngg−1 and CV at 2ngg−1. Average recoveries were 90.6% (±8.1% R.S.D., n =45) for LCV and 84.4% (±4.2% R.S.D., n =6) for CV. The average recovery for samples fortified with BG or LBG over the range 0.5–10ngg−1 was 67.2% (±14.8% R.S.D., n =31). CV and BG were confirmed in fish extracts by ion trap LC–mass spectrometry (LC–MS n ) with no discharge-atmospheric pressure chemical ionization. Average LC–MS n recoveries were 96.5, 96.6, and 70.2% for samples fortified with CV, LCV, and BG or LBG. The limits of detection for CV, BG, and MG were in the range of 0.07–0.24ngg−1 (ppb) for the two different instrumental methods. This methodology was applied to the analysis of catfish treated with CV and BG. [Copyright &y& Elsevier]

Abstract: Quinolones are a group of chemotherapeutic agents with an excellent efficiency against poultry pathogens. Two commercial enzyme-linked immunosorbent assay (ELISA) tests have been applied in parallel for the qualitative screening analysis of several quinolones in eggs, poultry muscle and feeds at the required levels. During the validation study, carried out according to the Commission Decision 2002/657/EC criteria, two different sample treatments were compared in foods: the simple and fast procedure suggested by the kit producer (Euro-Diagnostica) and a more complex solid-phase extraction (SPE) sample preparation. The results demonstrated that the method based on SPE clean up exhibited better characteristic performances, particularly in eggs for which lower detection levels are required. Despite the fact that screening methods should be rapid and cheap, the use of non-chromatographic techniques such as ELISA for multiresidual detection of a class of substances involves some additional attention to sample preparation. [Copyright &y& Elsevier]

Abstract: Residual feed intake (RFI) represents the deviation of the actual feed consumption of an animal from that predicted from combination of growth traits. Data on 1642 Duroc (380 boars, 868 gilts, and 394 barrows) pigs in seven generations were used to estimate genetic parameters for measures of RFI, daily feed intake (FI), average daily gain (ADG), backfat (BF), and loin eye area (LEA). Four measures of RFI were estimated from models that included initial test age and weight, and ADG (RFI1); initial test age and weight, ADG, and BF (RFI2); initial test age and weight, ADG and LEA (RFI3); and initial test age and weight, ADG, BF, and LEA (RFI4). Genetic parameters were estimated using an animal model by the REML method. Heritability estimates for measures of RFI were moderate (ranged from 0.22 to 0.38). The corresponding estimates for FI, ADG, and LEA were also moderate (ranging from 0.45 to 0.49), while the estimate for BF was high (0.72). Genetic correlations of FI with ADG (0.84) and BF (0.67) were high. LEA negatively correlated with FI (−0.42), ADG (−0.11) and BF (−0.44). Genetic correlations of BF with measures of RFI were higher when BF was not included in the estimation of RFI (0.77 with RFI1 and 0.76 with RFI3 vs. 0.11 with RFI2 and 0.07 with RFI4). Genetic correlations of LEA with measures of RFI were all negative (ranged from −0.30 to −0.60). Selection for ADG, LEA, BF, and intramuscular fat has resulted in small but favourable genetic changes in measures of RFI. Phenotypic correlations between measures of RFI were zero, and genetic correlations between them were low (0.17 to 0.23). FI was strongly correlated with all the measures of RFI, both genetically (ranged from 0.56 to 0.77) and phenotypically (ranged from 0.56 to 0.66). The results suggested that selection against RFI may cause a reduction in FI. BF should also decrease, and LEA should increase. The amount of change in BF or LEA would vary depending on whether RFI was adjusted for BF. [Copyright &y& Elsevier]

Abstract: Incoming legislation on the registration, evaluation, authorisation and restriction of chemical substances places responsibility on the chemical industry, including downstream users of chemicals, to provide appropriate safety information with which to improve the protection of human health and the environment through the better and earlier identification of the intrinsic properties of chemical substances. Food consumption is only one of several potential exposure routes, but if industrial chemicals enter the food chain, the diet may be a significant pathway of human exposure. Consequently strong measures are taken to protect the integrity of the human food chain and these are constantly revised to address perceived chemical safety threats. In order to understand the risk presented by the possible presence of a chemical residue in food, knowledge is required of its toxicology and of the level of exposure. Reliable exposure assessment requires robust analytical methodology. Existing standards for the validation and performance evaluation of methods have led to improved analytical capability and better inter-laboratory agreement of results. However, increasing the availability of robust, cost-effective methodology should be the benchmark for future developments in the field of food chemical residue analysis. Chromatography meets the needs of target analyses well and largely provides the selectivity of measurement needed to assess compliance with food regulatory limits. However, to keep pace with the increased need for expanded analytical capability – faster throughput, more analytes per sample – chromatographic separation capability still needs to grow. In this respect, orthogonal separation techniques and multi-dimensional chromatography are key tools for the future. [Copyright &y& Elsevier]

The concentrations of iron (Fe), copper (Cu), zinc (Zn), nickel (Ni), manganese (Mn), cadmium (Cd), lead (Pb) and chromium (Cr) in chicken meat, chicken gizzard and turkey meat consumed in southern Nigeria were determined after nitric acid/perchloric acid digestion using graphite furnace atomic absorption spectrophotometry. The order of the elements in the chicken meat, chicken gizzard and turkey meat was as followed: Fe>Zn>Ni>Cu>Cr>Pb>Cd>Mn. The concentration ranges of the elements were: 23.59-97.72 mg.kg-1 Fe; 0.01-5.15 mg.kg-1 Cu; 4.95-48.23 mg.kg-1 Zn; 0.13-7.93 mg.kg-1 Ni; 0.01-1.37 mg.kg-1 Mn; 0.01-5.68 mg.kg-1 Cd; 0.01-4.60 mg.kg-1 Pb and 0.01-3.43 mg.kg-1 Cr. The concentrations of iron, manganese, copper, zinc were below the permissible limits while those of cadmium, nickel, chromium and lead in some samples were at levels above the permissible limits. The body burden with these elements is very dependent on the concentration of the various elements in major sources of animal protein, namely turkey meat, chicken meat and gizzard, the frequency of consumption of these foods and the rate of detoxification in the human body. [ABSTRACT FROM AUTHOR]

Abstract: This paper describes a simple and sensitive method for determining alkylphenols namely 4-tert-octylphenol (4-t-OP) and the isomers of 4-nonylphenol (4-NPs) present in various types of baby-food purees. The method involves extracting a sample with n-hexane for 1h using a modified Nielson–Kryger steam distillation extraction system and then identifying and quantitating the alkylphenols using a gas chromatography–mass spectrometry (GC–MS) operated in the selected ion monitoring (SIM) mode. The extraction conditions were evaluated at various values of pH of the sample solution. The limits of quantitation for this method were 0.2ng/g from 1.0g (wet weight) samples of 4-t-OP and the 4-NPs. The intra- and interbatch precisions and accuracies were also determined. The precision, in terms of the relative standard deviation (RSD), were less than 8%. Most of the recoveries of the alkylphenols from various spiked samples exceeded 60%, while the values of RSD ranged from 1% to 10%. Alkylphenol residues were detected in baby-food purees at concentrations of up to 19ng/g (wet weight) for 4-t-OP and up to 21ng/g (wet weight) for the 4-NPs. [Copyright &y& Elsevier]

Investigations were undertaken to identify causes for the occurrence of high levels of the zootechnical feed additive nicarbazin in broiler liver at slaughter. The first investigation on 32 commercial broiler flocks involved sampling and analysis for nicarbazin (as dinitrocarbanilide, DNC) in liver from birds during a 3-10-day period after withdrawal of nicarbazin from their feed and before commercial slaughter. DNC residues in liver samples of broilers scheduled as being withdrawn from nicarbazin for ≥6 days ranged from 20 to >1600 µg kg-1 (the specified withdrawal period for nicarbazin is 5 days and the Joint Expert Committee on Food Additives (JECFA) maximum residue limit (MRL) is 200 µg kg-1 liver). Further on-farm investigations on 12 of these flocks, selected on the basis of the feeding system in use and the levels of DNC residues determined in liver, identified issues in feed management contributing to elevated residues in broiler liver. A significant correlation (0.81, p < 0.01, n = 10) between DNC residues in liver samples and in feed samples from the feeding pans was observed. The second investigation on 12 commercial broiler flocks involved sampling and analysis for DNC in liver samples and feed samples from feeding pans and from the feed mill at the three thinnings of birds for commercial slaughter. In the case of one flock, a clear relationship between nicarbazin in feed from the feed mill (10.5 mg kg-1 DNC), in feed from the feeding pans (6.6 mg kg-1 DNC) and in liver (583 µg kg-1 DNC) at first thinning (9 days scheduled withdrawal from nicarbazin) was observed. Such a clear relationship was not observed in other cases, particularly at second and third thinnings, pointing to re-exposure of birds to nicarbazin late in the flock production cycle, probably from the litter. Guidelines outlining best farm practice to eliminate nicarbazin residues in poultry have been published in booklet and poster format for broiler producers and deal with feed system cleaning, feed bin management, feed deliveries, feed usage and records. [ABSTRACT FROM AUTHOR]

Analytical methods for zeranol residues are reviewed. Zeranol was a widely used as an anabolic promoter, and it could give rise to very low residues in the edible tissues of food animals. Zeranol was officially banned in Europe due to safety concerns because of its potential carcinogenic and endocrine-disrupting biological activity. A few analytical methods for determination of zeranol are reported in the literature and most of the methods such as thin-layer chromatography (TLC), gas chromatography-mass spectrometry (GC/MS), high-performance liquid chromatography (HPLC), liquid chromatography-mass spectrometry (LC/MS) and immunoassay are reviewed in this paper. Specific aspects of analysing zeranol such as sample selection, sample handling, method selection and chromatographic conditions are discussed. The instrumental methods such as LC/MS and GC/MS provide sensitive and specific techniques, but are very laborious and expensive. These methods are suitable for confirmation but not for screening of large numbers of samples. A rapid, sensitive and specific assay is needed to detect positive samples in routine analysis, and immunoassay offers practical advantages over the conventional instrumental methods in rapid analysis of zeranol residues. Immunochemical methods such as enzyme-linked immunoabsorbant assay (ELISA) are simple, rapid and cost-effective, with adequate sensitivity and specificity to detect small molecules. This review can be considered as a basis for further research aimed at identifying the most efficient approaches for the analysis of zeranol. [ABSTRACT FROM AUTHOR]

A post-screening classification assay for tetracycline compounds has been developed and integrated into the previously reported optimized Premi®Test methodology. The new post-antimicrobial screening assay is based on a metal ion chelation using calcium and sodium chloride and has been shown to be specific towards the tetracycline class. The assay is both cost-effective and complementary to the post-screening procedures that have previously been developed for the β-lactam and sulfonamide compounds. A validation study was conducted in accordance with 2002/657/EC (Commission Decision). The method is rugged and applicable to a range of tetracyclines of differing antimicrobial potencies over a wide concentration range. A blind trial was undertaken in which all antimicrobial residues in the unknown samples were successfully identified by the analyst following the integrated Premi®Test procedure for the classification of antimicrobial compounds. [ABSTRACT FROM AUTHOR]

This paper evaluates whether the Swiss monitoring programme for foreign substances in animal products fulfils basic epidemiological quality requirements, and identifies possible sources of bias in the selection of samples. The sampling was analysed over a 4-year period (2002-05). The sampling frame in 37 participating abattoirs covered 51% of all slaughtered pigs, 73% of calves, 68% of beef and 36% of cows. The analysis revealed that some sub-populations as defined by the region of origin were statistically over-represented while others were under-represented. The programme that is in accordance with European Union requirements contained some relevant bias. Patterns of under-sampled regions characterized by management type differences were identified. This could lead to an underestimate of the number of contaminated animals within the programme. Although the current sampling was stratified and partially risk-based, its efficiency could be improved by adopting a more targeted approach. [ABSTRACT FROM AUTHOR]

The article describes a rapid method based on hot water extraction and liquid chromatography-tandem mass spectrometry (LC/MS/MS) for analyzing tetracycline antibiotic residues in cheese. This method is based on the matrix solid-phase dispersion technique followed by LC/MS/MS. The results suggest that the method could be applied to other cheese types not considered in this study.

Abstract: There exists the possibility that non-target livestock may receive trace exposure to medications in feed due to residue carryover from previous production runs of medicated feeds at feed mills. We have developed a method by which ADI-Derived Drug Carryover Levels (ADCLs) can be established. It is a practical approach compared to the “zero” levels of residue carryover that may be expected or required by regulatory authorities. The methodology involves application of various safety/uncertainty factors to concentrations of active ingredients (a.i.) already approved for use in medicated feeds for target species. The starting point for each a.i., to be consistent, and to represent the highest possible carryover, is the highest approved concentration for any target animal species, recognizing that this is an approved level based on established ADI and agency review of supporting safety data specific to each a.i. (Hence, these guidance values are characterized to be ‘ADI-derived’.) Safety factors are then applied to account for: (a) interspecies extrapolation, (b) differences in the body weights of target and non-target species (i.e., smaller animals receive higher exposures on a body weight basis for a given dietary concentration), (c) a.i. with clear contraindications for use in certain non-target species (i.e., a priori knowledge of non-target species sensitivity), and (d) withdrawal times (i.e., for a.i. that require a washout period prior to slaughter there is potential exposure to non-target species through other feeds not requiring a washout period). The values of the safety/uncertainty factors range from 1 to 3, 1 to 3.17, 1 to 10, and 1 to 10, for each of conditions (a), (b), (c), and (d), respectively. The “proposed safety factor” to apply to the approved concentration in medicated feed is calculated as the product of the values for each of (a) through (d). The final safety factor is the greater of the proposed safety factor or a default minimum safety factor of 30. ADCLs were calculated for several a.i. and compared to limits of quantitation available for detection of carryover residues in animal feeds. This methodology may be used in its present or modified form in any jurisdiction in which mediated feeds are approved. As a start, this approach has been applied to several example products approved and in use in Canada. [Copyright &y& Elsevier]

The human risk assessment of feed contaminants has often been hampered by a lack of knowledge concerning their behaviour when consumed by livestock. To gain a better understanding of the transfer of contaminants from animal feed to animal products, a meta-analysis of public literature was made. Data concerning feed contaminant concentrations, feeding periods, residue levels in animal products, and other parameters were gathered and recorded. For each case a ‘transfer factor’, which was defined as the ratio of the concentration of a chemical in an animal product to the concentration of the chemical in animal feed, was calculated. Scientifically founded transfer factors were calculated and analysed for groups of chemicals based on their contaminant classes or physicochemical properties. These database-derived transfer factors enable a more accurate risk assessment in the case of a feed contamination, and enable rapid risk management decision-making and/or intervention. [ABSTRACT FROM AUTHOR]