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Edible portions of 12 marine organisms from several areas of the Adriatic Sea, Italy, were collected during Spring 1997 and analysed for 32 organochlorine pesticides residues and 27 polychlorobiphenyl congeners. Only eight organochlorine pesticides - hexachlorobenzene (HCB), hexachlorocyclohexane (HCH) isomers, diphenyl-dichloro-trichloroethane (DDT) group, dieldrin - were determined at levels in the range <0.01-19.88 ng g[sup -1] wet weight, with 1,1'-dichloro-2,2'-bis(4-chlorophenyl)ethylene (DDE) being the more relevant single organochlorine. The contamination by organochlorine pesticides was comparable in organisms from the North, Centre and South Adriatic. Polychlorinated biphenyls (PCBs) were determined at levels in the range <0.05-14.46 ng g[sup -1], with CB 101, 118, 138, 153, 180 and 187 being more relevant (penta-, hexa- and hepta-chlorinated congeners). The sum of PCBs congeners determined were in the range 1.18-69.05 ng g[sup -1]. The contamination by PCBs is more relevant in organisms from the North Adriatic Sea owing to the antropic discharge from major rivers such as Po and Adige that flow through highly industrialized and densely populated areas. [ABSTRACT FROM AUTHOR]

Rapid, sensitive and selective method was studied for the determination of glyphosate in rice and wheat flour using a Raptor Polar column. Samples were extracted with acidified methanol solution. Isotope labeled internal standard was added with the extraction solvent to ensure accurate tracking and quantitation. The glyphosate was analyzed by liquid chromatography tandem mass spectrometry using a Raptor Polar column. Method performance was evaluated through a series of parameters that include accuracy, precision, linearity, limit of detection (LOD), limit of quantitation (LOQ) and matrix effect. Mean recoveries for all matrices were within 96-116% at three fortification levels. Precision for replicates was ≤19% relative standard deviation (RSD%) for wheat and ≤9% RSD% for rice across all fortification levels. Linearity was good for both matrices with a correlation coefficient >0.999 and residual <20% in the concentration range 0.025-1 mg kg -1 . LOD was 0.005 mg kg -1 for both rice and wheat flour and the LOQ was 0.05 mg kg -1 for both matrices. The matrix effect was also studied. A successful method for the analysis of glyphosate in wheat and rice flour assure that the criteria of acceptability of the maximum residue levels (MRLs) are insured.

The objective of this study consists of being able to develop a precise, reliable, easy, cheap and quick method to identify and quantify the presence of pesticide metabolites and their parents in human urine. In order to reach our purpose we selected the pesticides and their metabolites with intended uses on permanent crops such as orchards and vineyard. The activity planning started with the identification of the target list carried out by UHPLC-MS/MS and GC-MS/MS, succeeded by several tests oriented to determine the best sample treatment having recourse to instrumental analysis in the range 5-100 ng/mL. Several purifications were also investigated combining different adsorbents (PSA, EMR-lipid and final polish pouch). The use of formic acid during the extraction step has no impact on the recoveries, whereas the PSA adsorbent in the cleanup step negatively affects the results for all investigated metabolites. Any substantial differences were not observed in urine matrix for parent compounds achieving recoveries higher than 80% and RSD less than 20%. The final polish in combination or not with Enhanced Matrix Removal EMR-lipid did not show statistically significant difference in term of trueness and precision for both metabolites and parents, as evaluated by one-way ANOVA. The 3-OH THPI was the most critical compound with not acceptable results for linearity, trueness and precision.

In this work we report the results for estimating the measurement uncertainty (MU) following up the application of two different approaches, relatively the top-down procedure, by using proficiency test data. We have focused the estimation on the olive oil matrix. We used the analytical data obtained from five selected editions of the Proficiency Tests (PTs, from 2007 to 2011) on pesticide residues in olive oil to estimate the MU. These PTs have been organized by Istituto Superiore di Sanità annually in cooperation with International Olive Council (IOC) since 1997. The number of participants in each trial ranged from 10 to 43. We used a total of 34 pesticide results. The expanded uncertainty U(c) was calculated using a covering factor k = 2 for a confidence interval of 95%. In the approach 1, the within-laboratory reproducibility standard deviation is combined with estimates of the method and laboratory bias using PTs data. In the approach 2, the way of estimating the MU is based only on the bias that the laboratory has obtained participating in a sufficient number of the IOC proficiency tests. Comparing the relative expanded uncertainty based on these different approaches we notice values quite constant and close, from 42% to 48%. Moreover, these calculated expanded uncertainties are less than the default value of 50% (corresponding to a 95% confidence level), adopted from European guidance document SANCO based on the fit-for-purpose relative standard deviation (FFP-RSD).

In the analytical analysis the measurement uncertainty is a quantitative indicator of the confidence describing the range around a reported or experimental result within which the true value can be expected. Several approaches can be used to estimate the measurement uncertainty associated to the analysis of pesticide residues: a) the top-down, the estimation can be referred to default values; b) the bottom-up the estimation is related to the uncertainty sources. Concerning the bottom-up approach, the following contributions have been investigated: weight of sample, calibration solutions, final volume of sample and intermediate repeatability studies. The commodity/residue combination selected in this study was celery/tau-fluvalinate pesticide. Tau-fluvalinate is a broad-spectrum insecticide in the pyrethroid class of pesticides. The Maximum Residue Limit (MRL) of tau-fluvalinate in celery has been set at 0.01 mg/kg. The tau- Fluvalinate showed two chromatographic peaks. Since the individual standards are not available, the two peaks were integrated separately and the instrumental responses were added. The total residue was calculated on the basis of resulted peaks. The present work aims to compare the uncertainty estimated by experimental data using repeated analysis (n = 12) of a real sample and a spiked sample. The relative expanded uncertainty for two data set, incurred and spiked, was 22 % and 20 %, respectively. No differences were observed from repeated determinations of real samples and spiked samples.

Dimethyl fumarate (DMFu) is a substance with remarkable hygroscopicity and fungicidal power, which has recently showed to be a strong sensitizer to humans. The use of DMFu in little desiccant pouches, for e.g. in handbags or footwear boxes, might result in the contamination of leather products, with the subsequent exposure to consumers by contact. In 2009, 153 samples of desiccant material were collected from leather manufactures all over Italy and analyzed for DMFu. Results proved to fall in a wide range (0.14-7145 mg/kg).

A simple method for the determination of dimethyl fumarate (DMFu) in silica gel pouches has been developed. The gas chromatographic behaviour of DMFu was investigated; the instrumental method, based on EI mass spectrometry coupled with an Ion Trap Detector operating whether in full scan mode or in MS/MS mode was also investigated. Several factors have been evaluated and optimized during the development process: solvent and temperature of extraction, type of stationary phase in capillary column. The analytical procedure consists of two steps as follows: (a) the sample preparation using 10 g of sample extracted with acetonitrile in an ultrasonic, heated bath and (b) the determination by gas chromatography-ion trap mass spectrometry. Mass spectrometry in conjunction with chromatographic separation is a very powerful combination for identification of an analyte in the extract in spite of selective detectors employed with GC, such as ECD, FPD and NPD, that offer only limited specificity. Blank samples show no interfering peaks in the areas of interest, so the specificity of the method was assured under the investigated GC/MS conditions. The method has been validated in terms of recovery, repeatability, linearity, detection limits and measurement uncertainty. The results obtained meet both the method validation criteria and requirements of the European/National legislation. The method was verified to be accurate with 97 % mean recoveries at 0.05 mg/kg and 1.00 mg/kg levels; the repeatability (expressed as RSD %) was found to be better than 15 %. Good linearity was found in the range between 0.05 μg/mL and 5.0 μg/mL and a value of R² > 0.9998 was calculated. The procedure ensures high specificity and a good sensitivity with detection limit (ld) of 0.02 mg/kg and quantification limit (LOQ) of 0.05 mg/kg. This procedure has been successfully applied for the analysis of several hundred of real samples collected during a monitoring control plan started last year in our country. All samples exceeding the maximum allowed level of DMFu (0, 1 mg/kg) were confirmed by GC/MS/MS (ITD) for a higher degree of confidence in identification. The main advantages of this method include: rapidity, simplicity (few, simple steps), reliability, cheapness, no need for long and difficult clean-up and evaporation steps, high specificity by using GC/MS and GC/MS/MS, availability for routine monitoring.

A simple and rapid method has been studied for the determination of acidic herbicides (2,4-D, Dichlorprop, Dichlorprop-p, Fluazifop, Fluroxypyr, MCPA, Mecoprop and Mecoprop-p) on cereals (rye). The method involves an alkaline hydrolysis with sodium hydroxide in order to release covalently bound compounds, prior to QuEChERS extraction, followed by neutralization and analysis via liquid chromatography-double mass spectrometry LC/MS/MS. The performance of the method either with or without alkaline hydrolysis was studied in terms of recovery rates and limit of quantification (LOQ). In either case, recoveries were determined at four spiking levels (0.02 mg/kg, 0.05 mg/kg, 0.1 mg/kg and 0.5 mg/kg) with 5 replicates for each level. Mean recoveries ranged from 90 to 120 %, whereas relative standard deviations (RSD %) proved to be less than 20 %. Quantitative analysis was carried out by the internal standard (Nicarbazin) and the LC/MS/MS analysis was performed in electrospray ionisation (ESI) negative mode using a Zorbax XCB Eclipse column. The developed method was applied to the analysis of several cereals commercially available like as rye flour, oat meal, oat flakes and dehusked oat. Residue levels were found below the limit of quantification (LOQ) of the method. The method has been tested in EU Proficiency Tests for cereals with good results.

The development of an analytical method for the determination of four selected pyrethroid insecticides at residue level in beef meat is presented. Acetone and petroleum ether at 40-60 degrees C were chosen as extraction solvents. A two-step clean-up was performed using an Extrelut NT3-C(18) system followed by a Florisil column, with disposable, ready-to-use cartridges. Instrumental analysis was carried out on a gas chromatograph equipped with an electron capture detector (GC-ECD), using matrix-matched and internal standard calibration techniques. Confirmatory analysis by GC-MS was performed. Recoveries at the EU Maximum Residue Limit (MRL), 0.5 x MRL and 1.5 x MRL levels and the repeatabilities were widely satisfactory. The main advantage of the method was the reduction of analysis time as compared with previously published works. The applicability of the method to different matrices and pesticide classes will be investigated.

A method for the determination of toxaphene residues in fish and fish-based baby foods has been developed. The cleanup of the fatty matrices was performed using an acid treatment on an Extrelut-NT3 and ENVI-Florisil SPE cartridges system, using light petroleum as eluent. Instrumental analysis was carried out by gaschromatography with mass spectrometry detector (GC/MS) in SIM mode. Recoveries from spiked samples were tested at 0.005 and 0.01 mg/kg per single congener and were in the range 82-104% while relative standard deviations (RSDs) were in the range 3.7-10.9%. Nineteen samples of both frozen fish food and fish-based baby foods representative of the Italian market were collected from local dealers and analysed.

Fungicide residues in vegetables (benomyl, carbendazim, thiabendazole) are analyzed through a clean-up procedure that uses a portion of the aqueous acetone extract prepared for multiresidue methodology. A portion of the aqueous acetone extract (equivalent to 5 g of vegetables) is loaded onto an Extrelut-20 cartridge (the cartridge is filled with a coarse, large-pore diatomaceous material). Then, acetone is partially removed by an upward stream of nitrogen at 2l/min for 30 min. Benzimidazolic fungicides are recovered by percolating the cartridge with 100 ml of 0.1 M phosphoric acid solution, which also serves to convert benomyl to carbendazim. The percolating acid solution is drained on-line through a strong cation-exchange (SCX) solid-phase extraction cartridge with the aid of a slight vacuum. Benzimidazolic fungicides are retained on the SCX cartridge. The phosphoric acid solution is discarded together with the washings of the SCX cartridge, i.e., water followed by methanol-water (75:25), that remove unwanted coextractives. Finally, benzimidazolic fungicides are recovered by eluting the SCX cartridge with methanol-ammonium formate buffer (75:25). The final extract is then analyzed by reversed-phase HPLC with UV detection. Recoveries from crops such as apples, lettuce, strawberries and citrus fruits are generally greater than 80% and no interferences were observed. The clean-up is simple and straightforward, requires only disposable items, water solutions and a few milliliters of solvent and a minimum number of manipulations, and does not require concentration steps or electrical equipment.

The method studied uses a combination of a solid-matrix dispersion partition (SMDP) followed by high-performance size-exclusion chromatography on a minicolumn (HPmSEC) of 7.8 mm I.D. for the separation of pyrethroid (PYR) residues from fatty material. The solid-matrix dispersion extraction is carried out by absorbing a fat solution onto an Extrelut-3 cartridge (filled with a macroporous diatomaceous material) and extracting the PYR residues with acetonitrile. Up to 1 g of fatty material can be extracted with 15 ml acetonitrile. The small amount (mean +/- S.D. = 12.4 +/- 5.9 mg) of fatty material which is eluted into the acetonitrile is further removed by HPmSEC. PYR pesticide residues are collected in a 2-ml fraction between 7 and 9 ml, the column being washed up to 24 ml. The two techniques used in series allow a better removal of fat, a greater input of sample and a lower consumption of solvent compared to the sole SEC on macrocolumns, and a lower limit of determination compared to the sole SEC on minicolumns. Recoveries of 9 PYR out of the 14 investigated residues from soya oil were in the range 66-83% at spiking levels ranging 0.49-2.57 mg/kg, while for 6 PYR residues tested at spiking levels in the range 0.13-0.53 mg/kg the recoveries were in the range 80-111%. Recovery of fluvalinate and permethrin could not be calculated due to interferences from soya oil, while lambda-cyhalothrin, esfenvalerate and tralomethrin gave low recovery. The final extract contains small amount (mean +/- S.D. = 2.4 +/- 0.9 mg) of lipid residue and is not completely free from interferences.