• The Korean Journal of Pesticide Science
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• v.18 no.4
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• pp.278-295
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• 2014

Fast and accurate multi-residue pesticides inspecting method needs in Agro-Fishery Products Inspection Center. So, We tried to seek the optimum method using GC-TOF/MS, GC-ECD, GC-NPD after QuEChERS sample preparation. In GC-TOF/MS, 138 kinds of pesticide were spiked at 0.3 and $0.5{\mu}g/g$for the identification and quantification in lettuce sample. Recoveries of 77 pesticides were between 70 and 130% with RSD (relative standard deviation lower than 20% at $0.3{\mu}g/g$. In GC-ECD, NPD, 146 kinds of pesticide were spiked for the identification and quantification in lettuce. Recoveries of 61 species were between 70 and 130% with lower than 20%. These results indicated that GC-TOF/MS, GC-ECD, NPD analysis with the QuEChERS sample preparation can be partly applied to multi-residue pesticides in vegetables.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.10 no.1
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• pp.126-146
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• 2000

To develop and evaluate formaldehyde measurement method using 2,4-dinitro-phenylhydrazine (2,4-DNPH) coated sampler and gas chromatography, laboratory test and field test were conducted. Results of this study are as follows. Limit of detection(LOD) of measurement methods, HPLC-UVD, GC-NPD and GC-FID, is $0.008{\mu}g/m{\ell}$ $0.060{\mu}g/m{\ell}$, $0.472{\mu}g/m{\ell}$ respectively. Coefficiency of measurement methods, HPLC-UVD, GC-NPD and GC-FID, is 0.008, 0.009, 0.020 respectively. Desorption efficiency of sep-pak xposure aldehyde sampler and sorbent sample tube is 1.05(range : 0.99 - 1.12), 1.02(range : 0.99 - 1.06) respectively. Samples of sorbent sample tube and sep-pak xposure aldehyde sampler turned out to be stored at refrigerator, according to storage test results. Measurement methods of HPLC-UVD, GC-NPD, GC-FID, according to results of precision for the combined sampling and analytical procedure, became acceptable to OSHA evaluation standard. Field test using exposure chamber met the NIOSH overall uncertainty recommendation(less than 25%). Overall uncertainty of Sepak-HPLC(UVD), Tube-GC(NPD), Tube-GC(FID) is 11.0% - 17.0%. Consequently gas chromatography(GC-NPD, GC-FID) and high performance liquid chromatography(EPA TO-11) using 2,4-DNPH coated sampler for formaldehyde measurement turned out to be suitable to measure personal formaldehyde exposure at workplaces.

• Journal of Environmental Science International
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• v.6 no.2
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• pp.183-187
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• 1997

Organophosphate pesticides were extracted with 70% acetone and then transferred to dichloromethane. Extracts were applied to open-column chromatography with florisil. The florial extract was analyzed by gas chromatography with nitrogen-phosphorus detector(GC/NPD). Recoveries of the 18 organophosphate pesticides were ranged from 88.7% to 100. 0% for the narrow-bore capillary GC(Ultra-21. The minimum detectable level of this analytical method was 0.019 - 0.035 mg/kg. Sample throughput(extraction, open-column chro- matography, and GC analysts) was decreased considerably (8h per sample).

• Journal of Environmental Science International
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• v.6 no.4
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• pp.385-389
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• 1997

Pesticide residues were extracted with 70% acetone and transferred to dichloromethane. Extracts were applied to open-column chromatography with florisil and alumina-N. The final extract was analyzed by gas chromatography with electron-capture detector(GC /ECD) and nitrogen-phosphorus detector(GC/NPD). Recoveries of the 17 organochlorine pegticides were ranged from 60.8 to 84.9% and those of 15 organophosphate pesticides, from 70.5% to 100.0%(except phosmet and azlnphos-methyls. The minimum detectable levels of this analytical method were low(0.021-0.058mg/kg).

• Journal of Environmental Science International
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• v.12 no.10
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• pp.1117-1120
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• 2003

Pesticides were extracted from samples with 70% acetone and methylene chloride in order, and then cleaned up via open-column chromatography apparatus packed with florisil, and finally analyzed simultaneously the organophosphorus pesticides using GC/NPD. Ultra-2 and Ultra-1 fused silica capillary columns were used to separate and identify the products. Recovery of most analytes from soybean sample, taken from pesticide residues well, was greater than(80%) for all except(6) analytes. This method can simultaneously determine multiple pesticides with a high degree of accuracy and precision.

• YAKHAK HOEJI
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• v.37 no.1
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• pp.54-65
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• 1993

A method for the determination of 16 residual pesticides in crude deugs was examined. Crude drug was extracted with acetonitrile/water solution and the extract was partitioned between hexane/CH$_{2}$Cl$_{2}$ and NaCl saturated water. The organic layer was passed through cleanup column and subjected to the GC/ECD or GC/NPD analysis. Essential oil components in crude drug interfere with the analysis, and sulfuric acid treatment was adapted to overcome this interference.

• Food Science and Biotechnology
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• v.15 no.6
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• pp.959-966
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• 2006

The electron-capture detector (ECD) of gas chromatographs (GC) has been used widely in pesticide analysis. However, as ECD relies on radioactive material, it is troublesome to purchase and maintain. Therefore, potent replacements for ECD were investigated. A Pulsed-discharge detector (PDD) for ECD was tested and the analytical results of PDD (ECD mode), ${\mu}ECD$, and nitrogen-phosphorus detector (NPD) were compared for 107 pesticides including organochroline, organophosphorus, pyrethroids etc. The number of pesticides identified at the lowest limit of detection (LOD) was 36, 29, and 2 for PDD, ${\mu}ECD$, and NPD, respectively. The remaining pesticides showed same response to PDD and ${\mu}ECD$. The GC-PDD analysis of pesticides spiked into representative agricultural products (brown rice, spinach, and mandarin oranges) also showed good and/or equivalent recoveries using $GC-{\mu}ECD$.

• Korean Journal of Food Science and Technology
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• v.29 no.3
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• pp.427-431
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• 1997

A simultaneous and rapid gas chromatographic determination of organophosphorus, organo-chlorine, carbamate, and pyrethroid pesticides in polished rice was developed. The pesticides were extracted from samples with acetone by automated soxhlet apparatus and this extract was evaporated to dryness. The residue was dissolved in hexane, the solvent was applied to a Sep-Pak florisil catridge, was eluted with 50% ethyl acetate in n-hexane, and was injected to dual GC-ECD/NPD system. This simple method affords a high recovery of hydrophilic pesticides, allows rapid analysis, and is cheap to perform. Except for dichlorvos and captan, recoveries of 46 pesticides were over 60%.

• Analytical Science and Technology
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• v.25 no.6
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• pp.364-369
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• 2012

Isotianil is a novel fungicide which induces systemic acquired resistance in plants. It has excellent preventive effects as low dosages against rice blast which is one of the most serious diseases in rice. The Maximum Residue Limit (MRL) of Isotianil in republic of korea was set to 0.1 mg/kg in rice, so it is necessary to determine levels of Isotianil residues in agricultural commodities for controlling food safety. Therefore, The purpose of this study was to develop analytical method for the determination of isotiical residues in agricultural commodities using GC-NPD/MSD. Isotianil was extracted with acetonitrile from apple, chinese cabbage, hulled rice, mandarin, pepper, and soybean. The extract was diluted with saline water, and then dichloromethane partition was followed to recover this fungcide from the aqueous phase. A solid phase extraction with Florisil cartridge was additionally employed for final clean up. Isotianil was analyzed and quantitated by GC-NPD and confirmed by GC-MSD. Average recovery of Isotianil ranged from 70.0 to 103.9% in six representative agricultural commodities with relative standard deviations less than 10%, and limit of quantification (LOQ) was 0.05 mg/kg.

• Toxicological Research
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• v.7 no.1
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• pp.21-27
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• 1991

We developed a simple method to determine benzodiazepines in biological samples using electron capature detectors and nitrogen-phosphorous detectors. The extraction of 13 benezodiazepines in urine at pH 9.5 with toluene and its analysis in GC/NPD showed the peaks in 9-16 min. In this retention time range, the biological backaground was fairly low and the drugs could be identified in low concentrations. The benzodiazepines in urine samples were screened by the fluorescence polarization immunoassay and positive samples were confirmed by the GC/NPD method.