• The Journal of Korean Medicine
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• v.20 no.1 s.37
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• pp.44-51
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• 1999

Analysis of residual pesticides in herbal drugs was performed by GC-ECD and GC-MS. Especially, selected ion monitoring(SIM) technique was applied to increase the GC/MS sensitivity. Analysis of residual pesticides was determined sensitivity and selectively without any internal standard by setting the SIM technique to their characteristic fragments for quantitation ion and confirmation ion. The combination of two detector, GC-ECD and MS-SIM technique, is abailable for determining a multiclass residual pesticides in herbal drugs. The average recoveries through the method were $65.9%{\sim}99.7%$ in herbal drugs. The data of gas chromatographic analysis was compared with the limits of residual pesticides in herbal drugs and agricultural foods. 4. 4-DDT was detected above the limits to the residual pesticides in herbal drugs. Diazinon and EPN were detected, but the limits of residual pesticides were less than that of agricultural foods.

• YAKHAK HOEJI
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• v.40 no.2
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• pp.141-148
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• 1996

GC/MS analysis of 27 controlled pesticides in herbal drugs was studied. Selected ion monitoring(sim) technique was applied to increase the GC/MS sensitivity. Typical peaks in th e mass spectrum of each pesticides were selected as quantitation, comfirmation or alternate ion. Twenty seven pesticides were divided into five groups according to their retention time and the peaks for SIM were programmed accordingly. The combination of two ionization methods, electron impact(EI)-SIM-MS and negative ion chemical ionization(NCI)-SIM-MS, were well-fitted for the detection, confirmation and quantitation of multiclass residual pesticides in herbal drugs.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.19 no.1
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• pp.1-19
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• 1993

Gas chromatography serves to separate the mixtures into its components, and mass spectrometer is used to analyzing of unknown compounds. But there are many problems the identification of horn compounds using by GC only. As this reason GC/MS a very powerful analyzing technique. Mass spectrometer consists of 1) inlet stem 2) ion source 3) Bass filter 4) detectors and 5) data system. There are two analyzing modes in the GC/MS, those are scan and SIM(selected ion mom toping) modes. Scan mode is used when analyzing unknown compounds and SIM mode al lows the mass spectrometer to detect specific compound with very high sensitivity. As GC/MS applications for the analysis of cosmetic products, volatile compounds in lotion, earn foundation and hair color, and carbon distribution of fatty acids in soap were performed. Also as a new sample pre-treatment technique, head space sampler/GC/MS introduced in order to analyze the volatile compounds in a toothpaste.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.3
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• pp.312-321
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• 2015

Objectives: The purpose of this study was to determine the best method to analyze PAHs at extremely low concentrations. To this end, 16 PAHswere analyzed simultaneously by GC/MS, HPLC/FLD and HPLC/UVD, and the analytical characteristics of HPLC and GC/MS were compared. Methods: This study was conducted by GC/MS and HPLC/FLD/UVD, and evaluated linearity, precision and detection limit. Standard solutions were prepared for 21 samples in the range of $0.00001{\sim}1.0{\mu}g/mL$ and the samples were divided into four groups. All samples were made in three sets and analysis was replicated seven times. Results: Sixteen PAHs could be simultaneously separated by HPLC and GC/MS, and the adequate equipment was HPLC/FLD. The retention times by HPLC were shorter than GC/MS, and HPLC had better separation for most PAHs than GC/MS. The peaks of naphthalene and naphthalene-D8 partially overlapped for GC/MS. HPLC/FLD had a 20-2000 times lower limit of detection than GC/MS and UVD. However FLD was not adequate for analyzing acenaphthylene because it has too low a fluorescence quantum yield to be detected. The precision of HPLC/FLD/UVD and GC/MS showed less than 20% at $0.001{\mu}g/mL$ PAHs and when the concentration was higher, the coefficient of variation was decreased. HPLC/FLD was better for the overall detection of limits. Conclusions: The results indicate that the HPLC/FLD method has good linear range, precision and a detection of limits from $0.00001{\sim}0.0001{\mu}g/mL$ for all 16 PAHs. This study contributes to providing useful data for analysis technology and can be applied to occupational exposure measurement for PAHs in workplaces.

• The Korean Journal of Pesticide Science
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• v.20 no.2
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• pp.104-127
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• 2016

A new analytical method has been developed to determine 320 pesticides in apple and rice. The extraction of pesticides was carried out based on QuEChERS sample extraction, and determination was performed using LC-MS/MS and GC-MS/MS. 320 pesticides were selected for experiments. 251 and 110 pesticides among them were analysed by LC-MS/MS and GC-MS/MS, respectively. 41 pesticides of them were analyzed by both GC-MS/MS and LC-MS/MS. Among pesticides analysed by LC, 242 pesticides (96% of total number) in apple and 237 pesticides (94% of total number) in rice showed recoveries in the range of 70~120% with RSD ${\leq}20%$. In case of pesticides analyzed by GC-MS/MS, 103 pesticides (94% of total number) in apple and 83 pesticides (76% of total number) in rice were successfully validated. These results indicated that LC-MS/MS and GC-MS/MS analysis with the QuEChERS sample preparation can be partly applied to multi-residue pesticides in agricultural products.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2004.05a
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• pp.73-73
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• 2004

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.7 no.1
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• pp.17-23
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• 2009

Dihexyloctanamide(DHOA) was used as an extractant or phase modifier with the diamide extractants in a solvent extraction process for a radioactive liquid waste treatment. The degradation compounds of the DHOA extractant, irradiated with $^{60}Co$ gamma ray, were octanoic acid and dihexylamine which are identified by a Fourier transform infrared(FT-IR) and gas chromatograph/mass spectrometer(GC/MS) analysis, and determined by the GC/MS with selected ion monitoring(SIM) mode. Retention behavior of octanoic acid, tridecane (internal standard) and dihexylamine in total ion chromatogram (TIC) were 8.65 min., 9.79 min., and 10.27 min., respectively. With increasing the absorbed dose of the $\gamma$-ray irradiated DHOA, the concentration of octanoic acid was decreased and that of dihexylamine was increased.

• Analytical Science and Technology
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• v.23 no.4
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• pp.414-422
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• 2010

In forensic examinations of question document, analysis about inks components and the dating of ink entries is often of considerable importance and forensic examination of inks is principally concerned with the classification and comparison of chemically complex mixtures. The authenticity about inks analysis of a questioned document may be examined through the analysis of inks used to TLC, HPLC/MS, GC/MS, LDI/MS. We collected 56 difference types of black ballpoint pen inks manufactured from 5 country groups. We identified major 6 species volatile organic components (VOCs), ethylbenzene ($0.089-0.244\;{\mu}g$/mL), o-xylene ($0.072-0.331\;{\mu}g$/mL), m,p-xylene ($0.062-0.318\;{\mu}g$/mL), benzene ($0.003-0.173\;{\mu}g$/mL), 1,1-dichloroethylene ($0.003-0.295\;{\mu}g$/mL), toluene ($0.007-0.484\;{\mu}g$/mL) using HS-SPME GC/MS. The results of this study indicated that determined VOCs of black ballpoint pen inks could make a discriminating tool of inks analysis for forensic question document and can supply methodology for classification and identification of between ballpoints pen inks.

• Archives of Pharmacal Research
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• v.26 no.9
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• pp.697-705
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• 2003

The alkylphenols, chlorophenols, and bisphenol A were determined by gas chromatography/mass spectrometry-selected ion monitoring (GC/MS-SIM) followed by two work-up methods for comparison: isobutoxycarbonyl (isoBOC) derivatization and tert-butyldimethylsilyl (TBDMS) derivatization. Eleven endocrine disrupting chemicals (EDCs) of phenols in biological samples were extracted with acetonitrile and then the acetonitrile layer underwent freezing filtration 6$0^{\circ}C$ for 2 hours. Solid-phase extraction (SPE) was used with XAD-4 and subsequent conversion to isoBOC or TBDMS derivatives for sensitivity analysis with the GC/MS-SIM mode. For isoBOC derivatization and TBDMS derivatization the recoveries were 92.3∼150.6% and 93.8∼108.3%, the method detection limits (MDLs) of bisphenol A for SIM were 0.062 $\mu$ g/kg and 0.010 $\mu$ g/kg, and the SIM responses were linear with the correlation coefficient varying by 0.9755∼0.9981 and 0.9908∼0.9996, respectively. When these methods were applied to mackerel samples, the concentrations of the 11 phenol EDCs were below the MDL.

• Korean Journal of Food Science and Technology
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• v.29 no.5
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• pp.882-887
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• 1997

Quantitative determination of sulforaphane, S-methylsulfinylbutyl isothiocyanate in 20 cruciferous vegetables of Korean origin was performed. Homogenate of vegetable was extracted with dichloromethane, and the extract, after drying, was subjected to GC/MS analysis, which was based on single ion monitoring (SIM) at m/z 72, 160, 55, 114 and 177. The content of sulforaphane was found to be the highest in the extract of broccoli $(80.2{\sim}617.7\;ppm)$ followed by turnip $(15.4{\sim}23.1\;ppm)$, red cabbage $(9.9{\sim}32.1\;ppm),\;radish\;(5.5{\sim}8.8\;ppm)$ and kale (8 ppm). Among various cultivars of broccoli, broccoli '1243' and broccoli 'Pilgrim' showed higher content of sulforaphane than others. Especially, in the stem of broccoli '1243' and the floret of broccoli 'Pilgrim' the amount of sulforaphane was the highest (>700 ppm). Thus, the content of sulforaphane differed according to the cultivars and the portion of the vegetables.