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Background: Angelica dahurica Radix and Osterici radix, are perennial herbs belonging to the family Umbelliferae, which were attacked by red spiders, thus fenpropathrin was registered. Fenpropathrin is important in improving productivity and quality of medicinal herbs due to timely pest control. However, residue may likely remain after harvest, and therefore, the residue analysis is important to ensure pesticides safety management. Objective: This study aimed to establish analysis method for fenpropathrin residues in A. dahurica Radix and O. radix using GLC-ECD and GC-MS/MS. Methods: Samples were moisturized with distilled-water and extracted with acetonitrile. The interferences were removed using SPE cartridges and analyzed by GLC-ECD and GC-MS/MS. Results: Based on pre-experiment results, the analysis method was optimized using double-cleanup method (SPE-GCB/NH2 & SPE silica cartridges). Fenpropathrin peak confirmed by GC-MS at the same retention time and with its mass numbers. Nevertheless, the cleanup processes are laborious and require a rather long time. Thus, additional effortless analysis method was developed using the d-SPE method that can apply to highly selective and sensitive GC-MS/MS. The LOD of GC-ECD and GC-MS/MS was 0.1 and 0.01 ng, respectively. While the LOQ was 0.04 mg/kg for both. Linearity (r2) was > 0.998 (GLC-ECD) and 0.999 (GC-MS/MS). The recoveries at three spiking levels ranged 83.6-103.1% and 89.6-98.0% for A. dahurica Radix and O. radix, respectively. Conclusion: Accuracy of the improved method met the standard of the Korean Ministry of Food and Drug Safety. Therefore, the developed methods expected to be used for analyzing pesticide residues in herbal medicines in Korea and other countries.

The current study evaluated the efficacy of indigenous isolates of entomopathogenic fungi against the third larval instar of tomato leaf miner (Tuta absoluta Meirick; Lepidoptera: Gelechiidae). Four virulent isolates were subject to morphological and molecular identification and they were identified as; Beauveria bassiana isolate Hammad-R7 (Sudan) accession (MN598666); Beauveria bassiana isolate-Sud-afro-18ITS accession (MK046654); Beauveria bassiana isolate Sud-afro-2oITS accession (MK046652) and Purpureocillium lilacinum isolate Khartoum accession (MK046655). Efficacy test was done by larval dipping in the fungal suspension along with the commercial product Eco-Bb®. Mycosis test was performed to confirm the growth of fungus from the cadaver. Treated larvae died within three days after the appearance of the symptoms. The four indigenous isolates showed medium mortality responses (LT50 ranged between 4.1–4.3 days) close to or slightly even better than that induced by the commercial product ECO-Bb (LT50 4.2 days) however three of them induced superior responses (LT90 ranged between 9.5–11.7 days) to the commercial product ECO-Bb (LT90 14.4 days) at higher doses measured at the LT90. Endophytic capability of the isolates was tested by seed dipping and soil drenching methods and the fungal mycelia was detected microscopically in the leaves and stems without apparent negative effects on plant growth. The current results indicate the promising potential of these isolates in the regulation of T. absoluta.

Pesticides have been used for decades to protect agricultural products and increase productivity by controlling crop pests. However, the frequent application of pesticides on crops or soil leads to the accumulation of their residues in the environment, which will be subsequently absorbed by plants and finally translocated to edible parts. This study aimed to investigate the uptake of soil-applied dinotefuran and three major metabolites by lettuce and celery from the previous season’s applications and analyze their residues in soil and consumable parts. Dinotefuran was soil-applied at plant back intervals of 30 and 60 days (PBI-30 and PBI-60). Residues of dinotefuran and its metabolites in 50% and 100% mature lettuce leaves and celery shoots, soil after application, at planting, and at 50% and 100% plant maturity were estimated. Half-lives and bio-concentration factors were calculated. The uptake of dinotefuran by lettuce and celery ranged between 23.8% and 28% and between 51.73% and 53.06%, respectively. Respective half-lives (days) of dinotefuran applied on PBI-30 and PBI-60 were 1.33–1.54 and 0.91–2.16 in lettuce soil and 0.9–1.47 and 0.79–1.65 in celery soil. Residues were below Korean MRLs in PBI-60 and most PBI-30 samples. The calculated risk assessment parameters indicated that negligible risk could be expected. The current study recommends growing the next crop 60 days after harvesting the first crop, but not less than 30 days.

Integrated management of BT cotton pests was carried in field experiments during the seasons; 2016/2017 (Season I) and 2017/2018 (Season II) in the experimental research farm of Kassala University, Sudan. Four insecticides (imidacloprid, abamectin, profenofos and lufenuron) and three levels of soil applied nitrogen; 43.81 kgha−1, 87.62 kgha−1 and 131.43 kgha−1 were tested at recommended doses. Seven weekly counts of abundant pests (whitefly, jassid, aphid, and mealybug) were done starting 4 weeks before spraying. Post spray counts were done after 3, 10 and 17 days from spraying. Seed cotton yield of various treatments was recorded and economic analysis of the package was calculated. Results indicated that increasing the nitrogen dose result in significant increase in population of sap sucking pests during the pre-spray counts while insecticide treatments significantly reduced the infestation level in the post spray counts. Aphid was found in season I while mealybug was found in season II only in contrast to whitefly and jassid which were found in both seasons. Imidacloprid was the most effective insecticide causing reduction in the level of infestation by the various sap sucking pests in the range of 11.20% -71.66%, followed by lufenuron (with reduction in infestations level ranging between 8.12% to 69.11%) and profenofos (with infestation reduction ranging between 9.88% to 66.74%). On the other hand abamectin was the least effective treatment causing the least infestation reduction in the population of sap sucking pests (ranging between 8.38% to 66.45%). No significant interactions were found between nitrogen and insecticide treatments. Highest seed cotton yield and revenue was associated with imidacloprid combined with various nitrogen levels (causing 46%–63% increase), followed abamectin nitrogen treatments (7%–22%), profenofos and lufenuron nitrogen combinations. Generally, seed cotton yield increases by the increase of nitrogen dose, while the revenue (net benefit) depends on the price of the insecticide used.

This study was carried out to isolate and identify indigenous bacteria associated with pesticides heavily contaminated soil in Sudan. The samples were collected from pesticides contaminated soil in different locations. The predominant bacterial isolates were then purified by subculturing on selective media. Seven isolates were selected based on their capability to degrade pesticides and three of them having the highest performance in biodegradation of frequently reported pesticide contaminants were subject to identification by molecular tools using 16S rDNA gene sequence analysis. Amplification of 16S rDNA gene was done from genomic DNA and sequenced. Construction of phylogenetic tree was done after aligning of multiple sequences. The results reveal that the three bacterial isolates are Bacillus cereus ATCC 14579, Bacillus subtilis subsp. inaquosorum KCTC 13429 and Bacillus safensis FO-36b. This is the first record of pesticides biodegradation by B. safensis FO-36b which can be considered as a novel contribution in this field. Since these strains were found effective and are living naturally in an environment heavily contaminated with pesticides, therefore, they might have potential in removing pesticides from contaminated soils, especially soils of pesticide stores and dumping sites in developing countries. Key words: Bacillus, gene sequencing, pesticides-polluted soil, Sudan.

This study was performed to investigate the residual characteristics, safety assessment, and pre-harvest interval (PHI) of spiromesifen and chromafenozide in lettuce (Latuca sativa L.) and perilla (Perilla frutescens (L.) Britton) leaves. Samples were harvested periodically, extracted using QuEChERS method, and analyzed by LC-MS/MS. Average recoveries of spiromesifen and its metabolite BSN2060-enol and chromafenozide were ranged from 80.6 to 107.9%, with relative standard deviation

The knowledge of eggplant farmers on the proper use of pesticides was evaluated in Khartoum State. Questionnaire was distributed to farmers in North Nile Farms (NN), East Nile Farms (ENF), and West Nile Farms (WNF) to solicit information. Interviews and questionnaires revealed that there is a limited level of awareness among farmers. The majority (94%) of farmers did not abide by recommended disposal procedures, they only damage and bury the containers inside the farms. The majority of farmers (66%) were not aware of the safety period for any given product. The excessive use of pesticides in eggplant production and reliance only on pesticides as a pest management strategy calls for the implementation of IPM programs integrating the use of environmentally soft chemicals with other non-chemical control methods to manage pests and diseases. Safety periods should be carefully watched to reduce the level of residues in eggplant fruits below the acceptable level and to ensure sustainable and safe production.

Field assessment of integrated management of BT cotton pests was carried out in two consecutive seasons; 2016/2017 and 2017/2018 in the experimental research farm of the Kassala University, Sudan. Four insecticides (imidacloprid, abamectin, profenofos, and lufenuron) from different chemical groups and with a different mode of action and three levels (43.81 kgha-1, 87.62 kgha-1, and 131.43 kgha-1) of soil-applied nitrogen were tested in the IPM package. Insecticides were applied at the recommended doses. A total of 7 weekly counts of prevailing natural enemies [Chrysoperla carnea (Stephens) and Aenasius bambawalei Hayat] were carried out for 4 weeks before spraying and 3 weeks post spraying starting the 3rd week from spraying. Results indicated that nitrogen level exerted no significant effects on the populations of prevailing natural enemies; C. carnea and A. bambawalei. Based on average post spray counts and percentage reduction over the control, all insecticide treatments significantly reduced the population of the natural enemies. Imidacloprid and profenofos exerted the highest reduction of C. carnea population followed by abamectin and lufenuron (56.03, 48.25, 07.78 and 06.61% respectively) in the first season, while profenofos, imidacloprid, lufenuron, and abamectin induced the highest reductions (55.94, 45.05, 17.57 and 17.33% respectively) in the second season. On the other hand, reductions in A. bambawalei population (abundant in season 1 only) followed the order; imidacloprid, lufenuron, abmectin, and profenofos (03.95, 02.63, 202.63, and 01.32%, respectively). Interactions between nitrogen fertilization and insecticide were not significant as measured by the population of prevailing natural enemies.

This study evaluated the potential antioxidant and antidiabetic properties in vitro of four millet grain varieties cultivated in South Korea. The free fractions were tested for their total antioxidant capacity using 2,2&prime, azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS+) and 2,2&prime, diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assays, followed by &alpha, glucosidase, &alpha, amylase, and advanced glycation endproducts (AGEs) formation inhibition assays. The total phenolics, flavonoids, and condensed tannins in the free fractions ranged from 107.8 to 136.4 mg ferulic acid equivalent (FAE)/100 g, 101.3 to 115.8 mg catechin equivalent (CE)/100 g, and 17.65 to 59.54 mg catechin equivalent (CE)/100 g, respectively. Finger Italian millet had the highest total phenolic content (136.4 mg FAE/100 g) and flavonoid content (115.8 mg CE/100 g). Barnyard and finger Italian millet showed the highest DPPH (IC50 = 359.6 &micro, g/mL and 436.25 &micro, g/mL, respectively) and ABTS radical scavenging activity (IC50 = 362.40 &micro, g/mL and 381.65 &micro, g/mL, respectively). Similarly, finger Italian millet also exhibited significantly lower IC50 values for the percentage inhibition of &alpha, glucosidase (18.07 &micro, g/mL) and &alpha, amylase (10.56 &micro, g/mL) as compared with acarbose (IC50 = 59.34 &micro, g/mL and 27.73 &micro, g/mL, respectively) and AGEs formation (33.68 &micro, g/mL) as compared with aminoguanidine (AG) (52.30 &micro, g/mL). All eight phenolic compounds identified in finger Italian millet were flavonoids, with flavanols being the predominant subclass. Taken together, millet flavonoids play important roles in the prevention and management of type 2 diabetes, and hence finger Italian millet has the potential to be developed as a functional food.

The objective of this study was to evaluate the capability of the bacteria Bacillus safensis strain FO-36bT isolated from pesticide-polluted soil in degrading fenthion and temphos in mineral salt media (MSM). Fenthion and temphos were incubated with the isolated bacteria. Samples were drawn at 0, 3, 7, 14, and 30 days to analyze residual fenthion and temphos content with gas chromatography (GC) and high-performance liquid chromatography (HPLC), respectively. The loss of the initial pesticide concentration (400 mg/L) over time was determined and used to compute the half-lives using a biphasic model. Gas chromatography-mass spectrometry (GC-MS) was used to identify the major metabolites as well as to re-confirm the identity of starting material (fenthion). The results showed that the bacterium was still viable at the end of each incubation period. The biodegradation of fenthion and temphos followed a biphasic model. The half-lives of fenthion in the first and in the second phase were 0.29 and 3.69 days, respectively, whereas the corresponding values for temphos were 0.11 and 1.15 days. Only one metabolite "iso-fenthion" (O, S-dimethyl O-[3-methyl-4-(methylthio)phenyl] phosphorothioate) was detected in fenthion culture, while no metabolites were detected in temphos culture. Based on the half-lives, this bacterium was able to degrade temphos at a faster rate than fenthion. Key words: Biodegradation, fenthion, temphos, bacteria, pesticides-contaminated soil, Sudan.

The toxic effects of butachlor and oxadiazon, widely used herbicides in South Korea were evaluated in the common carp Cyprinus carpio. Fingerlings of C. carpio were exposed to 0.5, 5 and 50 µg L-1 concentrations of herbicides for 96 h under static bioassay method and hematological and biochemical parameters were assessed. At all concentrations of butachlor and oxadiazon, white blood cell (WBC), serum sodium (Na+), chloride (Cl-), glucose, cholesterol and triglyceride levels were significantly (P

Biodegradation of endosulfan (α and β) and pendimethalin by Bacillus safensis strain FO-36bT, Bacillus subtilis subsp. inaquosorum strain KCTC 13429T and Bacillus cereus strain ATCC14579T isolated from pesticides-polluted soil was studied in mineral salt medium. Endosulfan and pendimethalin were incubated with the three bacterial strains with samples drawn at various intervals for GC analysis. Representative samples were subject to GC–MS analysis. The loss in the initial concentrations, 0.663 mM (α endosulfan), 0.319 mM (β endosulfan) and 1.423 mM (pendimethalin), was monitored and used to compute the half-lives following biphasic model. Removal percentage of endosulfan and pendimethalin in the media inoculated with the bacterial strains ranged from 24 to 95% (α endosulfan), 21–91% (β endosulfan) and 51–97% (pendimethalin), respectively. Despite the significant decrease in starting material in B. safensis cultures, no metabolites were detected, whereas two major metabolites of endosulfan, 1,2,3,4,7,7-hexachloro-5,6-dihydroxybicyclo{2.2.1}-2-heptene and 1,2,3,4,7,7-hexachloro-formaldehyde-6-methylbicyclo{2.2.1}-2-heptene, were detected in the B. subtilis cultures, and one metabolite of pendimethalin metabolite; N-(1-ethylpropyl)-3-methyl-2, 6-diaminobenzine, was detected in the B. cereus culture. Generally, the result indicates the potential capability of these microorganisms in complete mineralization of endosulfan and pendimethalin. Based on half-lives, the efficiency of bacterial strains can be ordered as follows: B. subtilis > B. cereus > B. safensis for endosulfan and B. cereus > B. safensis > B. subtilis for pendimethalin.

Six representative Korean strains of streptomycetes (S33, S27, S71, S63, S77, and S78) that were pathogenic to potato were characterized based on phenotypic properties, analysis of 16S rRNA genes, production of thaxtomin A, and presence of nec1 and ORFtnp gene homologs. Strains S33 and S27 had typical characteristics of Streptomyces scabies and S. turgidiscabies, respectively, producing thaxtomin A and hybridizing to genes of nec1 and ORFtnp. Strain S71 produced thaxtomin A and had phenotypic and phylogenetic properties similar to those of S. acidiscabies, except having a greater minimum growth pH (4.5), production of a melanoid pigment on tyrosine agar, and failure to hybridize with nec1 and ORFtnp gene probes. In contrast, strains S63, S77, and S78 were phenotypically different from described scab pathogens. Spore colors of strains S63 and S77 were yellow-white or pale orange, respectively, with rectiflexuous chains. Strain S78 had thin and compact spores unlike typical S. acidiscabies (ATCC 49003). Phylogenetic analysis of strains S63, S77, and S78 based on 16S rRNA gene sequences showed low homology to that of described scab pathogens (less than 97.3, 96.0, and 96.3%, respectively). Strain S78 produced thaxtomin A, but did not have homologous sequences to nec1 and ORFtnp genes. Production of thaxtomin A and gene homologs of nec1 and ORFtnp were not detected in strains S63 and S77. All three strains grow at low pH, with minimal growth at pH 3.5 (S77 and S78) or 4.5 (S63). Streptomyces strains S63, S77, and S78 are novel pathogenic streptomycetes adapted to acidic soil conditions in Korea.

The potential of sunlight photolysis in remediation of pesticide-polluted soils in Sudan was studied. Chlorpyrifos, malathion and dimethoate, common pollutants, were exposed to sunlight over glass and soil surfaces with periodic samples drawn for GC and GC-MS analysis. Photo-degradation followed a biphasic model. Alpha half-lives of direct photolysis over glass surface range between 1.99 and 9.36 days while the range in soil surfaces is 1.88–10.77 days. Respective values for indirect photolysis with β-carotene are 0.96–2.40 days whereas for benzophenone are 0.38–2.37 days (not including malathion as starting material was completely lost after 3 days). Values for soil β-carotene sensitized photolysis are 0.85–4.02 days while respective values for soil benzophenone sensitized photolysis are 0.88–3.74 days. Metrological factors did not have a significant impact on photolysis rates. No photoproducts detected in direct photolysis. However, many photoproducts were detected on the indirect sets. Photo-degradation efficiency can be ordered as; benzophenone > β-carotene > direct exposure.

A fed-batch bioreactor based on sulfur-oxidizing bacteria (SOB) was tested for rapid detection of heavy metal-induced toxicity in water. For this evaluation, SOB were exposed to water contaminated by selenium, mercury, hexavalent chromium, arsenic, cyanide, cadmium, and lead for 2 h and their inhibition rates were analyzed based on changes in electrical conductivity (EC). The results demonstrate that SOB were highly inhibited by selenium, mercury, hexavalent chromium, and arsenic but not by cyanide, cadmium, and lead. The 2 h half maximum effective concentrations (EC50) of SOB for selenium, mercury, hexavalent chromium, and arsenic were estimated to be 0.33, 0.89, 1.18, and 0.24 mg/L, respectively, which are comparable or lower than earlier reports in the literature. However, the EC50 or EC20 values of SOB for cyanide, cadmium, and lead were notably higher compared to findings from previous toxicity tests that employed other microorganisms. The findings from the current study suggest that the fed-batch SOB bioreactor is suitable for rapid detection of toxicity induced by selenium, mercury, hexavalent chromium, and arsenic in water.

This study was conducted to examine the translocation of highly residual agrochemical in soil, the endosulfan (total), to ginseng (Panax ginseng C. A. Meyer). The soil with the level of the amount of 5.0 mg kg−1 of endosulfan (total) was prepared in a Wagner pot into which the seedling of ginseng was transplanted and then the specimens of ginseng (root, leaf, and stem) were collected quarterly and analyzed through GC-MS. The level of residual of endosulfan (total) in the soil has decreased from 4.28 mg kg−1 (April 2013) to 1.94 mg kg−1 (December 2014) while the level in the specimens of leaf and stem of ginseng respectively sampled according to its growth phase in June and September from 2013 and 2014 showed an increase from 0.56 mg kg−1 (June 2013) to 2.46 mg kg−1 (September 2013) and decrease from 0.29 mg kg−1 (June 2014) to 0.18 mg kg−1 (September 2014). For the case of the root of ginseng, the level of the amount of 10.77 mg kg−1 of endosulfan (total) was detected in June 2013 and then, the level has decreased to the level of 4.88 mg kg−1 in December 2014. The translocation of residual endosulfan (total) in soil to ginseng with time was identified. The amount of residuals of α-endosulfan and β-endosulfan was also decreased with time however, the ratio of endosulfan-sulfate, the main metabolite, was gradually increasing. The retention of metabolite (endosulfan-sulfate) in soil identified thereby thus suggests the potential of its translocation to plants in the case of the soils containing the residual of endosulfan (total).

This study was conducted to compare STQ method, multi-residue method in Korean food code and QuEChERS method for validated selected and accuracy, reproducibility and efficiency. A total of 45 selected and targeted pesticides were the analyzed by GC and 5 of them were crops (apple, potato, green pepper, rice, soy bean). R 2 values were calculated in the standard calibration curve was over 0.990. Recovery tests were performed by three replications in two levels and the relative standard deviation of the repeated experiments was less than 30%. The average percentage of recoveries in the multi-residue method in Korean food code was 89.13%, QuEChERS method was 92.45% and STQ method was 85.28%. In addition, matrix effects in multi-residue method in Korean food code was 24.61%, QuEChERS method was 23.98% and STQ method showed 11.24%. The STQ method is easy and showed high clean-up effect in extracting the sample solution than the QuEChERS method and clean-up with C18, PLS, PSA cartridge columns. A large volume of the sample was injected in order to compensable for the problem, that occurred due to high detection limit in the analyser. When the STQ method was applied using a large volume injector, the standard calibration curve showed a higher linearity R 2 =0.990, and method detection limit was 0.01 mg/kg. It showed an average recovery of 91.84% and the relative standard deviations of three replications repeated in two level process was less than 30% and had an average matrix effect of 17.90%.

BACKGROUND: The present investigation was aimed to predict the pre-harvest residue limits (PHRLs) of the fluopicolide and metrafenone on cherry tomato and to estimate their half-life and characteristics of the residues.METHODS AND RESULTS: Pesticides were treated once on cherry tomato in field 1 and 2 under the standard application rate. The samples were collected 7 times at the end of 0(2 hours after pesticides spaying), 1, 2, 3, 5, 7 and 10 days before harvest. Residues of fluopicolide and metrafenone were analyzed by the LC-MS/MS. In this study, the method limit of quantification (MLOQ) for both fluopicolide and metrafenone in cherry tomato was found to be 0.005 mg kg-1. Their recovery levels were 92.7∼94.8% and 82.6∼88.0%, shown with coefficient of variation of less than 10%. Half-life of fluopicolide and metrafenone in field 1 and 2 were found to be 15.0 days and 12.8 days, 18.9 days and 21.5 days, respectively.CONCLUSION: Based on the results, this study shows the level of PHRL on cherry tomato is 0.27 mg/kg for fluopicolide and 2.29 mg/kg for metrafenone at 10 days before harvesting. The present study indicates the residues of both pesticides on cherry tomato will be below maximum residue limit (MRL) at harvest.

The present study was aimed to predict the pre-harvest residue limits (PHRLs) of pyrimethanil (fungicide) and methoxyfenozide (insecticide) in grape, and to estimate their biological half-lives and residual characteristics. The pesticides were sprayed once on grape in two different fields 10 days before harvest. At the end of 0, 1, 2, 3, 5, 7 and 10 days after application, samples were harvested for further analysis. The residual pesticides were extracted with acetonitrile and partitioned with dichloromethane, and the high- performance liquid chromatography with diode array detector (HPLC/DAD) was employed for the residue analysis. The results obtained in the present study show that the limit of detection of both pesticides were found to be 0.01 mg kg �1 . The recoveries of these pesticides were ranged between 80.6% and 102.5% with coefficient of variation lower than 10%. The biological half-lives of both pesticides were observed in field 1 and field 2 which shows 7.7 and 7.4 days for pyrimethanil and 5.1 and 6.1 days for methoxyfenozide, respectively. Further, the PHRL of pyrimethanil and methoxyfenozide was found to be 8.90 mg kg �1 and 5.51 mg kg �1 , respectively at 10 days before harvest. Consequently, the present study suggests that the residual amounts of both pesticides will be lower than the maximum residue limits (MRLs) when grape is harvested.

Extensive use of fungicides in agriculture has led to the detrimental effects on aquatic ecosystems and organisms even at very low concentrations. In this respect, the present study was aimed to investigate the impact of environmentally relevant concentrations of fungicide isoprothiolane (2.7 and 27 µg/L; reported concentration in Yung San River, Korea) on a freshwater fish Cyprinus carpio for a short-term period of 96 h using various biomarkers such as hematological, ionoregulatory, biochemical, and enzymological parameters. At both concentrations, hemoglobin, hematocrit, red blood cell, serum glucose, cholesterol, triglycerides, aspartate aminotransferase, and gill Na+/K+-ATPase levels were significantly (p

Acute (24 h) and sublethal (35 days) effects of cadmium chloride (CdCl2) were examined in Cirrhinus mrigala using various endpoints (accumulation pattern, thyroid hormones (THs), and antioxidants). The mean concentrations of CdCl2 for 24 and 96 h were found to be 35.974 and 22.387 mg L−l, respectively. LC50 concentration of CdCl2 for 24 h (35.97 mg L−l) was used for the acute study. For the sublethal studies, fish were exposed to 3.59 mg L−1 (Treatment I) and 7.19 mg L−1 (Treatment II) corresponding to 1/10th and 1/5th of 24 h LC50 of the CdCl2. During acute exposure, higher accumulation of CdCl2 was noticed in the gill, liver, and kidney of C. mrigala, which is found in the order gill > liver > kidney tissues. Similarly, in sublethal treatments (Treatment I and II), a concentration and time-dependent increase of CdCl2 accumulation was noticed in the order of gill > liver > kidney. GSH, GST, and GPx activities were found to be relatively lower from the treated groups in both acute and sublethal treatments. However, LPO activity was significantly increased in CdCl2-treated fish C. mrigala. Further, plasma T3 reduction was more pronounced than T4 in acute study. During sublethal treatments, both T4 and T3 levels showed a continuous decrease as the exposure period extended. All the values in this study were statically significant (P

The transfer pattern of chlorpyrifos present in soil to cucumber plants were assessed and reportedwith plant growth, concentration dependency, and duration. Cucumber seedlings cultivated in a growthchamber for 30 days and a greenhouse for 120 days. Weight and length of cucumbers cultivated in thechamber increased with the increasing time, while the uptake of chlorpyrifos by cucumber increased a periodfrom 0 to 15 days and decreased after 15 days. Uptake rates of chlorpyrifos into a cucumber plant were 1.0~1.3% to initial amounts treated with 20 and 40 mg/kg to soil. Most chlorpyrifos residues were detected inroot, followed by stem and leaf. Results of the greenhouse test showed that chlorpyrifos amounts incucumber fruits were present less than LOQ (0.02 mg/kg), and chlorpyrifos was mainly found in the root ofthe cucumber plant. Chlorpyrifos absorbed in a cucumber under greenhouse condition was smaller than thatin chamber condition as 0.03~0.04%. Degradation patterns of chlorpyrifos in soils were similar during indoorand outdoor tests with half-lives of 25.8~73.0 days. These results may be useful for establishing themanagement strategy of residual pesticides in soil environment.Key words chlorpyrifos, cucumber, plant uptake, residual distribution, soil management strategy

Recently, some of the previous studies reported that tolclofos-methyl is still exist in ginseng cultivated soil, even though it is has been banned for ginseng. Therefore, the current study was aimed to examine the levels of absorption and translocation of tolclofos-methyl from ginseng cultivated soil to ginseng root and leaf stem for the period of 1 year. For this study, ginseng plants were transplanted in pots and treated with of tolclofos-methyl (50% WP). At the end of each interval periods (every three months) the samples (soil, roots and leaf stems) were collected and analyzed the absorption and translocation levels of tolclofos-methyl using gas chromatography and mass spectrometry (GC-MS). The limit of quantitation of tolclofos-methyl was found to be and 70.0~120.0% recovery was obtained with coefficient of variation of less than 10% regardless of sample types. In this study, a considerable amount of translocation of tolclofos-methyl residues were found in soil (4.28 to ), root (7.09 to ) and leaf stem (0.79 to ). The results show that the tolclofos-methyl was absorbted and translocated from ginseng cultivated soil to ginseng root and ginseng leaf stem and found to be decreased time-coursely. Secondly, we were also analyzed soil, root and leaf stems samples from Hongcheon, Cheorwon, Punggi and Geumsan by GC-MS/MS (172 pesticides), LC-MS/MS (74 pesticides). In this study, 43 different pesticides were detected () in soil, root and leaf stem. Further, tolclofos-methyl was detected 4 times separately in root sample alone which is less () than their maximum residual limit (MRL) in ginseng. Consequently, the results from both studies indicate the residues of tolclofos-methyl found in ginseng cultivated soil and ginseng ensuring their safety level. Moreover, long-term evaluations are needed in order to protect the soil as well as ginseng free from tolclofos-methyl residues.

The present work was aimed to determine the pre-harvest residue limits (PHRLs) and the safety management of commonly used pesticides namely buprofezin and penthiopyrad on oriental melon (Cucumis melon var. makuwa). In this study, the buprofezin (diluted two thousand fold) and penthiopyrad (diluted four thousand fold) were sprayed single time on oriental melon in the cultivation areas Sangju (site 1) and Sungju (site 2). Oriental melon were randomly collected from the both areas at the end of 0 (2 hours after pesticides spaying), 1, 2, 3, 5, 7, 9 and 10 days. For analysis, each samples were partitioned twice (80 and 70 mL) with dichloromethane and purified by florisil SPE cartridge. Finally, the residual amounts of both pesticides in all samples were analyzed using gas chromatography/nitrogen phosphorus detector (GC/NPD). In this study, the method limit of quantification (MLOQ) for both buprofezin and penthiopyrad in oriental melon was found to be 0.01 mg kg and their recovery levels were 91.1~98.6% and 90.0~104.6%, respectively. Further, the calculated biological half-life for buprofezin and penthiopyrad in oriental melon were 3.9 and 3.5, and 3.0 and 2.7 days in site 1 and 2, respectively. The results of this study found that the PHRLs for buprofezin and penthiopyrad were 4.24 and 2.31 mg kg, respectively at 10 days before harvest. Consequently, the present study suggest that the residual amounts of both pesticides will be lower than the maximum residue limits (MRLs) when oriental melon is harvested.

Among pre-harvest environmental factors, increasing attention has been paid to the effects of chemical and microbiological factors on fresh produce. The occurrence and prevalence of these factors have been usually studied with regard to the final products at the post-harvesting stage and/or when they are sold in the market. However, the origin and routes of transmission of both factors remain to be clarified. In the present study, we examined the contamination levels of food-borne pathogens and chemical factors such as pesticide residues and heavy metals in 83 and 43 samples, respectively, including various soil, water, and fertilizer samples, as well as post-harvested and processed samples. Among the organic farming samples, only one pesticide, dimethomorph, was detected in the soil sample, however no pesticides were observed from any other samples in organic farming system. Thus, it was thought that might be contaminated from conventional farm land in the vicinity. Whereas many pesticide residues were detected in conventional farming systems such as soil, fertilizer, water, and fresh produce as expected. Furthermore, heavy metals detected from all tested samples did not shown contamination levels higher than the standard limit. We comparatively assessed the levels of contamination by food-borne pathogens on the samples from organic and conventional farming systems, and found aerobic bacteria at approximately 7 log CFU/g, with no significant differences observed between the two systems. Coliforms were present at lower levels than aerobic bacteria. No human pathogens were present among the coliforms detected, indicating that these bacteria are saprophytes without the ability to cause food-borne illnesses. In contrast, among the high-risk food-borne pathogens, only sporadic cells of Bacillus cereus were found on samples of organic farming system. These data extend previous findings that the most prevalent food-borne pathogen is B. cereus and demonstrate that it spreads to whole living plants via soil.

In the present study, we developed an official individual analytical method for cymoxanil usingHPLC/UVD, respectively in different representative crops. Individual analytical methods for these pesticidesare not included in the Korea food code. The samples were extracted with acetonitrile, concentrated andpartitioned with dichloromethane and saturated sodium chloride solution. For cymoxanil, extracts wereconcentrated and clean-up through silica gel column chromatography with dicloromethane/acetone (60/40 v/v)and subjected to instrumental analysis. The limit of detection (LOD) for cymoxanil were 0.1 ng and 1 ngrespectively and limit of quantitation (LOQ) were 0.02 mg/kg. Recoveries for cymoxail ranged from 79.6~107.6% respectively, at fortification level of 0.02 mg/kg (LOQ), 0.2 mg/kg (10 LOQ) and 1.0 mg/kg(50 LOQ) and the coefficient of variation (CV) was less than 10%, regardless of sample types. These resultswere further confirmed with LC/MS. The proposed simultaneous analysis method is reproducible andsensitive enough to determine the residues of cymoxanil in the agricultural commodities. According to thevalidation data and performance characteristics and high sample throughput, the proposed method is suitablefor routine application.Key words analytical method, Cymoxanil, HPLC/UVD, LC/MS

The present study was performed to investigate the pre-harvest residue limit (PHRL) of pesticides namely, metalaxyl-M and flusilazole in oriental melon, and to identify the biological half-life and characteristics of their residues. In this study, pesticides were sprayed once as single spray and double spray on oriental melon. The oriental melon samples were collected at 0, 1, 2, 3, 5, 7, 9 and 11 days before harvest and samples were extracted with QuEChERS method. The residues of both the pesticides were quantified using GC/NPD and LC/MS/MS. The limit of detection was found to be 0.02 mg/kg and 0.01 mg/kg and their recoveries were greater than 95% (95.7% ~ 103.2% for metalaxyl-M and 100.2% ~ 106.8% for flusilazole) for both pesticides. The biological half-lives of both metalaxyl-M and flusilazole were 12 days at single and double spray, respectively. The PHRL of metalaxyl-M and flusilazole was found 1.0 mg/kg and 0.3 mg/kg, respectively for 10 days before harvest. The results of the present study shows the residual level of both the pesticides metalaxyl-M and flusilazole in oriental melon were less than their maximum residual limits.

BACKGROUND: Consensus of heavy metal phytoavailability in soils needs to be introduced for soil management protocols in relation to safer food production in the contaminated agricultural soils. For this, setting up the method for evaluation of metal phytoavailability in soil is an essential prerequisite. METHODS AND RESULTS: The current study was carried to select a proper single extraction method for determination of phytoavailable metal concentration in soil. Two extraction methods were examined including 1 M extraction and 0.01 M extraction methods using 142 soil samples collected from the agricultural soils nearby abandoned mining area in Korea. Corelation analysis was conducted between phytoavailable metal concentrations and soil properties potentially influencing on the metal phytoavailability. Both methods showed similar significance (p extraction rather than using extraction. CONCLUSION(S): It appeared that 0.01 M extraction was better option for determination of phytoavailable metals in soils and further study to test the efficiency of this method is required in combination with plant uptake.

This study was performed to investigate pre-harvest residue limit (PHRL) in amaranth, toestimate biological half-life of emamectin benzoate and identify the characteristics of the residue. Pesticidesof standard and double appplication rate, were sprayed once on amaranth at 0, 1, 2, 3, 5, 7, 10 ,14 daysbefore harvest. Amaranth sample was extracted with acetonitrile and partitioned with dichloromethane, andpesticide residues were determined with LC/MS/MS. The limit of detection of emamectin benzoate was 0.01mg/kg. Recoveries of emamectin benzoate (B 1a , B 1b ) at two fortification levels of 0.1 and 0.5 mg/kg, B 1a were93.3 ± 0.7% and 93.2± 7.7%, B 1b were 106.6 ± 1.9% and 80.5± 6.6%, respectively. The biological half-livesof emamectin benzoate were about 2.0 days at standard application rate and 1.7 days at double applicationrate, respectively. The PHRL of emamectin benzoate were recommended as 0.84 mg/kg for 10 days beforeharvest.Key words Amaranth, Emamectin benzoate, Pesticide residue, Pre-harvest residue limit