• The Korean Journal of Pesticide Science
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• v.17 no.1
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• pp.1-5
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• 2013

This study was conducted to the amount of pesticide residue in 21 different kinds of 100 commercial flowering teas. Multi-residue analyses of 203 pesticides was performed using the GC-ECD, GC-NPD, GC-MSD, and LC-MS/MS. Pesticide residues were detected in 4 samples (4%) of which 4 samples (4%) violated the maximum residue limits. 4 samples violating the limit were all imported teas. Pesticides detected were chlorpyrifos, flufenoxuron, lufenuron, pyrimethanil and methoxyfenozide. These results indicate the need of continuous monitoring of pesticide residue needs for safety of flowering teas.

• Korean Journal of Environmental Agriculture
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• v.32 no.1
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• pp.61-69
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• 2013

BACKGROUND: This survey was done to investigate the pesticide residues and to assess their risk on agricultural products on the Markets in Incheon from 2010 to 2012. METHODS AND RESULTS: The total number of samples were 16,025 for agricultural products and these were analyzed by multi-residue method using GC-ECD/NPD, GC-MS, LC-MS/MS and HPLC-PDA/FLD. The violation rates of the samples over maximum residue limits(MRLs) of pesticide residues established by Korean Food and Drug Administration in the survey of 2010, 2011 and 2012 were 1.2%, 0.8% and 0.7%, respectively. CONCLUSION(S): Of the total violated samples, more than 75% of the rates were recorded from the samples of leafy vegetables. Most commonly encountered agricultural commodities over MRLs were Chwinamul, perilla leaves and crown daisy. The pesticides detected yearly over MRLs during three years were endosulfan, chlorpyrifos, diazinon, lufenuron, chlorothalonil, flutolanil, procymidone, ethoprophos. Estimated daily intakes compared to acceptable daily intakes, except radish and Welsh onion, is estimated less harm on human in 10 kinds of pesticides which frequently occurred violation.

• The Korean Journal of Pesticide Science
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• v.17 no.4
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• pp.314-334
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• 2013

This study explored an efficient modified Quick, Easy, Cheap, Effective, Rugged and safe (QuEChERS) method combined with liquid chromatography-electrospray ionization with tandem mass spectrometric detection for the analysis of residues of 76 pesticides in brown rice, barley and corn including acidic sulfonylurea herbicides. Formic acid (1%) acid in acetonitrile and dispersive solid phase extractions used for extraction of pesticides and clean-up of the extract respectively. Two fortified spikes at 50 and 200 ng $g^{-1}$ levels were performed for recovery test. Mean recoveries of majority of pesticides at two spike levels ranged from 73.2 to 132.2, 80.9 to 136.8, 66.6 to 143.5 for brown rice, barley and corn respectively with standard error (CV) less than 10%. Good linearity of calibration curves were achieved with $R^2$ > 0.9907 within the observed concentration ranged. The modified method also provided satisfactory results for sulfonylurea herbicides. The method was applied to the determination of residues of target pesticides in real samples. A total of 26 pesticides in 36 out of 98 tasted samples were observed. The highest concentration was observed for tricyclazole at 1.17 mg $kg^{-1}$ in brown rice. This pesticide in two brown rice samples exceeded their MRLs regulated for rice in republic of Korea. Except tricyclazole none of the observed pesticides' concentration was higher than their MRLs. The results reveal that the method is effectively applicable to routine analysis of residues of target pesticides in brown rice, barley and corn.

• Journal of Food Hygiene and Safety
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• v.35 no.2
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• pp.136-145
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• 2020

This study was conducted to evaluate pesticide residues and foreign metallic matter on a total of 104 powdered agricultural products in Incheon. Residue testing for 373 pesticides was conducted by GC-MS/MS, LC-MS/MS, GC-ECD, GC-NPD and HPLC-UVD. Foreign metallic matter was detected by magnetic rod. As a result pesticide testing, 7 of the 104 products were found to be within the MRL of the pesticides. The detected pesticides were chlorpyrifos, etofenprox, fenoxanil, malathion, permethrin, tebuconazole and tetraconazole. As for foreign metallic matter, 16 samples were above the allowable limits set by Korean regulations. Therefore, the inspection of residual pesticides in raw material, and the removal of foreign metallic matter will require further stringent attention for the safety of powdered agricultural products.

• Journal of Food Hygiene and Safety
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• v.35 no.4
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• pp.365-374
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• 2020

This study was conducted to monitor the residual pesticides on a total of 320 stalk and stem vegetables from January 2019 to December 2019 in the Incheon metropolitan area. Pesticide residues in samples were analyzed by the multi-residue method for 373 pesticides using GC-MS/MS, LC-MS/MS, GC-ECD, GC-NPD and HPLC-UVD. Risk assessment was also carried out based on the amount of stalk and stem vegetables consumed. The linearity correlation coefficient for the calibration curve was 0.9951 to 1.0000, LOD 0.002 to 0.022 mg/kg, LOQ 0.005 to 0.066 mg/kg and recovery was 82.0 to 108.0%. According to the monitoring of pesticides, 36 (11.3%) of 320 were detected with pesticide residues and 3 (0.9%) samples exceeded the maximum residual limit. The detection frequency for Chinese chives and Welsh onion was higher than that for other stalk and stem vegetables. The frequently detected pesticides were etofenprox, procymidone, fludioxonil, and pendimethalin. As a tool of risk assessment through the consumption of pesticide detectable agricultural products, the ratio of estimated daily intake (EDI) to acceptable daily intake (ADI) was calculated in the range of 0.0062-24.1423%. These results indicate that there is no particular health risk through consumption of commercial stalk and stem vegetables detected with pesticide residues.

• Korean Journal of Food Science and Technology
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• v.53 no.4
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• pp.470-478
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• 2021

This study was conducted to monitor residual pesticides in a total of 527 school foodservice agricultural products from 2019 to 2020 in Incheon. Pesticide residues in the samples were analyzed by the multi-residue method in the Korean food code for 373 pesticides using GC-MS/MS, LC-MS/MS, GC-ECD, GC-NPD, and HPLC-UVD. By monitoring the pesticides, 12 (2.3%) of the 527 pesticides were detected, and 2 (0.4%) samples exceeded the maximum residue limit. Twelve types of pesticides were detected in the agricultural products of carrot, chard, chili pepper, chwinamul, crown daisy, parsley, perilla leaves, and spinach. As a means of risk assessment through the consumption of agricultural products detected with pesticide residues, the proportion of estimated daily intake to acceptable daily intake was estimated in the range of 0.0000-39.7425%. Results showed no particular health risk through the consumption of school foodservice agricultural products with pesticide residues.

• Journal of Soil and Groundwater Environment
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• v.17 no.1
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• pp.42-46
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• 2012

The ISO document of ISO/TC/190/SC3/WG11/N11 is a working draft of international standard (WD) dealing with analytical method for the determination of explosives and related compounds using high performance liquid chromatography. The scope of this WD covers the storage of samples, preparing test portion, extraction and instrumentation. The main purpose of this study was to improve the extraction conditions which were already adopted in the WD. For this purpose, mechanical shaking method could be corresponded up to 18 hours of ultrasonic bath extraction in the WD was tested. Methanol was also tested with the intention of being added as an extracting solvent other than acetonitrile in the WD. According to the results, 16 hours of mechanical shaking method showed statistically the same effectiveness as that of 18 hours of ultrasonic bath extraction. In case of extracting solvent, methanol also showed statistically the same extraction capability as acetonitrile for DNB, TNT, 2-A-DNT and 2,4-DNT. However, the recovery rate of TNB with methanol extraction was 40% higher than that of acetonitrile extraction. Through adding mechanical shaking method into committee draft (cf. the next stage draft of the WD during the process for making international standard), ISO standard of analyzing explosives and related compounds in soil would become more useful in dealing with huge number of field samples in the laboratory. In other aspect, adopting methanol as an alternative extracting solvent would be very effective in the terms of exchangeability with GC-ECD/MS method which is being developed by German experts.

• Journal of Food Hygiene and Safety
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• v.32 no.3
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• pp.211-216
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• 2017

A total of 100 seafoods commonly consumed in Gyeonggi-do were investigated to determine the concentration of lead (Pb), total mercury (Hg), methyl mercury (MeHg), cadmium (Cd) and selenium (Se). Concentration of heavy metals and selenium was measured by using mercury analyzer, ICP-MS and GC-ECD. The average content (mg/kg) of heavy metals in the seafood samples was as follows; Pb 0.0915 (0.0021-0.4490), Cd 0.0084 (ND-0.1773), and Hg 0.0412 (0.0013-0.3032). All the levels were below the recommended standards of the MFDS in Pb (0.5 mg/kg), Cd (0.2 mg/kg), Hg (0.5 mg/kg). The methylmercury was detected in the hairtail (0.0677 mg/kg) and cod (0.2941 mg/kg). After the average content of heavy metals in seafood was determined, the exposure assessment for heavy metals was conducted. Relative hazardous levels compared to PTWI were lower than the official standards of the JECFA for Pb (0.97%), Hg (3.42%) Cd (0.45%). In conclusion, the levels presented in this study are presumed to be safe for consumption.

• The Journal of Korean Medicine
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• v.31 no.4
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• pp.9-19
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• 2010

Objective: To compare the contents and transfer rate of hazardous substances in crude, washing solution, crude after washing, decoction and remnant after boiling. Methods: The heavy metal contents of each step were measured by inductively coupled plasma mass spectrometer (ICP-MS) and mercury analyzer (SP-3DS). In order to analyze pesticides in each sample we used simultaneous multi-residue analysis of pesticides by GC/ECD, which was followed by GC/MSD analysis to confirm the identity of the detected pesticide in each sample. In addition, the contents of sulfur dioxide ($SO_2$) were performed by Monier-Williams distillation method. Results: 1. Contents (mg/kg) of heavy metals were not detected in decoctions of any tested herbal medicine prescriptions. 2. Transfer rates (%) of heavy metals from crude to remnant were as follows: Yijin-tang (As: 46.9, Cd: 50.0 and Pb: 100.0), Oryung-san (As: 80.0, Cd: 100.0 and Pb: 73.8), Hwangryunhaedok-tang (As: 88.9, Cd: 71.4 and Pb: 92.7), Bangpungtongseong-san (As: 100.0, Cd: 17.3 and Pb: 56.1), Oyaksungi-san (As: 47.4, Cd: 175.0 and Pb: 142.4). 3. Contents (mg/kg) of residual pesticides were not detected in any samples. 4. Transfer rate (%) of sulfur dioxide ($SO_2$) from crude to remnant in all samples were as follows: Yijin-tang (25.0), Oryung-san (166.7), Hwangryunhaedok-tang (50.0), Bangpungtongseong-san (181.8), Oyaksungi-san (50.0). Conclusion: Our results showed that the boiled herbal medicine prescriptions which we take are safe from the hazardous substances.

• The Korean Journal of Pesticide Science
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• v.15 no.2
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• pp.140-148
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• 2011

The official analytical method of residue pesticides in herbal medicines by KFDA cannot be applied to all of the pesticides and herbal medicines because of various active materials in herbal medicines and various physicochemical properties of pesticides. Moreover, liquid-liquid partition uses harmful solvents such as methylene chloride and is consuming a lot of time and effort. In order to improve the problems, we have studied for the availability of the analytical method applying the macroporous diatomaceous earth (MDE) column instead of liquid-liquid partition to simultaneously analyze five pesticides in two dried herbal medicines. The results showed that the recovery rates of acetamiprid and azoxystrobin in Astragalus root by GC/ECD ranged from 89.6 to 94.1%, from 86.8 to 94.4%, respectively, and those of bifenthrin, chlorfenapyr, chlorpyrifos in Cnidii Rhizoma by GC/MS ranged from 83.6 to 88.4%, from 77.4 to 83.8%, from 82.6 to 84.3%, respectively. Also, the coefficients of variation (CV) for triplication ranged from 0.5 to 1.7%. The results satisfied the criteria of residue pesticide analysis, setting 70~120% for the recovery rate and below 10% for the coefficient of variation. The improved methods are safer to residue pesticide analysts, faster and less laborious than the KFDA official method.