Liquid Chromatography and Gas Chromatography

Liquid Chromatography and Gas Chromatography, Total:200 items.

The international standard classification for "Liquid Chromatography and Gas Chromatography" includes: Chemical analysis , Protection against crime , Analytical chemistry , Other standards related to optics and optical measurements , Cereals, pulses and derived products , Meat, meat products and other animal produce , Chemical technology (Vocabularies) , Fruits. Vegetables , Sugar and sugar products , Beekeeping , Surface active agents , Vegetables and derived products , Farming and forestry , General methods of tests and analysis for food products , food products in general .

The Chinese standard classification for "Liquid Chromatography and Gas Chromatography" includes: Basic standards and general methods , Crime judging technology , chromatograph , Food sanitation , Basic standards and general methods , Sugar refining , Beekeeping, silkworm keeping , Tooth paste, soap and detergent , Legal medical expert , Basic standards and general methods , Pesticide management and application method .

General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China

GB/T 4946-2008 Terms of gas chromatography
GB/T 46325-2025 Determination of Free Sulfur Content in Vulcanized Rubber - Gas Chromatography (GC) and High Performance Liquid Chromatography (HPLC)
GB/T 21317-2007 Determination of tetracyclines residues in food of animal origin—LC-MS/MS method and HPLC method
GB/T 39880-2021 Examination methods for methadone in suspected drugs -- Gas chromatography and gas chromatography-mass spectrometry
GB/T 19426-2003 Method for the Determination of 304 Pesticides Residues in Honey,Fruit Juice and Wine―GC-MS and LC-MS-MS
GB/T 26792-2019 High performance liquid chromatography
GB/T 39877-2021 Examination methods for diazepam in suspected drugs—Gas chromatography and gas chromatography-mass spectrometry
GB/T 19427-2022 Determination of 12 phenolic compounds in propolis— HPLC-MS/MS method and HPLC method
GB/T 39885-2021 Examination methods for triazolam in suspected drugs - Gas chromatography and gas chromatography-mass spectrometry
GB/T 10410.3-1989 Analysis of liquefied petroleum gas composition by gas chromatography
GB/T 30433-2021 Standard column used for evaluating liquid chromatograph
GB/T 39882-2021 Examination methods for methylene dioxymetham phetamine in suspected drugs -- Gas chromatography and gas chromatography-mass spectrometry
GB/T 32122-2015 Determination of 12 nitroimidazoles in toothpaste―HPLC and HPLC-MS/MS
GB/T 39884-2021 Examination methods for three components in cannabis in suspected drugs - Gas chromatography and gas chromatography-mass spectrometry
GB/T 19648-2005 Method for determination of 446 pesticides residues in fruits and vegetables-GC-MS and LC-MS-MS
GB/T 39881-2021 Examination methods for methaqualone in suspected drugs -- Gas chromatography and gas chromatography-mass spectrometry
GB/T 30431-2013 Gas Chromatograph for Laboratory
GB/T 30433-2013 Standard Column Used for Evaluating Liquid Chromatography
GB/T 39883-2021 Examination methods for morphine in suspected drugs - Gas chromatography and gas chromatography-mass spectrometry
GB/T 39876-2021 Examination methods for cocaine in suspected drugs—Gas chromatography and gas chromatography-mass spectrometry
GB/T 16631-1996 General rules for analytical methods of liquid column chromatography
GB/T 9008-2007 Terms of liquid chromatography—Column chromatography and planar chromatography
GB/T 9008-2024 Terms for liquid chromatography
GB/T 4946-1985 Terms of gas chromatography
GB/T 29636-2013 GC ,HPLC and GC-MS examination methods for methylamphetamine in suspected drug
GB/T 30431-2020 Gas chromatography for laboratory
GB/T 30430-2019 Standard column used for evaluating gas chromatographs
GB/T 29635-2013 GC and GC-MS examination methods for heroin in suspected drug
GB 9008-1988 Terms of liquid chromatography; Liquid column chromatography and planar chromatography
GB/T 30433-2021(XG1-2023) Standard chromatographic column for liquid chromatography testing
GB/T 39878-2021 Examination methods for estazolam in suspected drugs - Gas chromatography and gas chromatography-mass spectrometry
GB/T 39879-2021 Examination methods for five components in opium in suspected drugs - Gas chromatography and gas chromatography-mass spectrometry
GB/T 9008-1988 Terms of liquid chromatography--Liquid column chromatography and planar chromatography
GB/T 19649-2005 Method for determination of 405 pesticides residues in grains―GC-MS and LC-MS-MS method
GB/T 39874-2021 Examination methods for bromazepam in suspected drugs—Gas chromatography and gas chromatography-mass spectrometry
GB/T 30430-2013 Standard Column Used for Evaluating Gas Chromatography
GB/T 19650-2005 Method for determination of 437 pesticides residues in animal tissues―GC-MS and LC-MS-MS method
GB/T 16631-2008 General rules for high performance liquid chromatography
GB/T 39875-2021 Examination methods for chlordiazepoxide in suspected drugs—Gas chromatography and gas chromatography-mass spectrometry
GB/T 26792-2011 High performance liquid chromatography
GB/T 29637-2013 GC and GC-MS examination methods for ketamine in suspected drug

Professional Standard - Judicatory

SF/T 0113-2021 Determination of cyanide in blood by gas chromatography-mass spectrometry and gas chromatography

Professional Standard - Public Safety Standards

GA/T 1631-2019 Forensic sciences—Examination methods for mirtazepine and fluoxetine in blood and urine samples—GC and GC-MS
GA/T 2029-2023 Forensic sciences-Examination methods for buprenorphine in suspected drugs-LC and LC-MS
GA/T 1637-2019 Forensic sciences—Examination methods for four sulfonylurea herbicides including metsulfuron in blood samples—LC and LC-MS
GA/T 2032-2023 Forensic sciences-Fxamination methods for dihydroetorphine in suspected drugs-GC and GC-MS
GA/T 1646-2019 Metsa T-Test Liquid Chromatography and Liquid Chromatography-Mass Spectrometry in Suspected Drugs in Forensic Science
GA/T 2025-2023 Forensic sciences-Examination methods for 5-MeO-DiPT and 5-MeO-MiPT in suspected drugs-LC and LC-MS
GA/T 1008.12-2013 GC and GC-MS examination methods for drugs—Part 12:Chlordiazepoxide
GA/T 1327-2016 GC, GC-MS and LC-MS/MS examination methods for zolpidem in biological samples in forensic science
GA/T 1008.2-2013 GC and GC-MS examination methods for drugs—Part 2:Morphine
GA/T 1789-2021 Forensic sciences-Examination methods for hydroxylimine in suspected precursors-LC-MS,GC-MS and HPLC
GA/T 1008.7-2013 GC and GC-MS examination methods for drugs—Part 7:Methaqualone
GA/T 2026-2023 Forensic sciences-Examination methods for phencyclidine in suspected drugs-GC and GC-MS
GA/T 1008.4-2013 GC and GC-MS examination methods for drugs—Part 4:Cocaine
GA/T 1008.8-2013 GC and GC-MS examination methods for drugs—Part 8:Triazolam
GA/T 1321-2016 GC and GC-MS examination methods for penthidine and its metabolite in biological fluid in forensic science
GA/T 1316-2016 GC and GC-MS examination methods for ketamine in hair and blood samples of forensic science
GA/T 1616-2019 Forensic sciences—Examination methods for chloramphenicol in biological samples—HPLC and LC-MS
GA/T 1615-2019 Forensic sciences—Examination methods for clozapine in biological samples—GC and GC-MS
GA/T 2034-2023 Forensic sciences-Examination methods for caffeine in suspected drugs-GC and GC-MS
GA/T 2024-2023 Forensic sciences-Examination methods for 5-MeO-DiPT and 5-MeO-MiPT in suspected drugs-GC and GC-MS
GA/T 2039-2023 Forensic sciences-Examination methods for tramadol in suspected drugs-LC and LC-MS
GA/T 2040-2023 Forensic sciences-Examination methods for promethazine insuspected drugs-LC and LC-MS
GA/T 2028-2023 Forensic sciences-Examination methods for buprenorphine in suspected drugs-GC and GC-MS
GA/T 1318-2016 GC and GC-MS examination methods for morphine and acetylmorphine in urine in forensic science
GA/T 187-2021 Forensic sciences-Examination methods for dichlorvos and trichlorfon in biological samples-GC-MS and LC-MS
GA/T 1623-2019 Forensic sciences—Examination methods for aldicarb in biological samples-GC-MS and LC-MS
GA/T 1328-2016 GC and GC-MS examination methods for carbamazepine in biological samples in forensic science
GA/T 1619-2019 Gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry for the detection of methomyl and methomyl oxime in forensic science biological samples
GA/T 1629-2019 Paraquat detection in blood and urine for forensic science by gas chromatography and gas chromatography-mass spectrometry
GA/T 2035-2023 Forensic sciences-Examination methods for caffeine in suspected drugs-LC and LC-MS
GA/T 1784-2021 Forensic sciences—Examination methods for a-PBP, a-PVP and 4-F-a-PVP in suspected drugs—LC and LC-MS
GA/T 1934-2021 Forensic sciences-Examination methods for six ephedrine classsubstances including norephedrine in suspected precursors-GC-MS,LC and LC-MS
GA/T 2031-2023 Forensic sciences-Examination methods for dolantin in suspected drugs-LC and LC-MS
GA/T 2023-2023 Forensic sciences-Examination methods for 5F-AMB and 5F-APINACA in suspected drugs-LC and LC-MS
GA/T 1645-2019 Liquid Chromatography and Liquid Chromatography-Mass Spectrometry for the Detection of Cocaine in Suspected Drugs in Forensic Science
GA/T 1620-2019 Forensic sciences—Examination methods for chlorpheniramine in biological samples—GC and GC-MS
GA/T 1008.9-2013 GC and GC-MS examination methods for drugs—Part 9:Estazolam
GA/T 1008.6-2013 GC and GC-MS examination methods for drugs—Part 6:Methadone
GA/T 1989-2022 Forensic sciences—Examination methods for promethazine in suspected drugs一GC and GC-MS
GA/T 2027-2023 Forensic sciences-Examination methods for phencyclidine in suspected drugs-LC and LC-MS
GA/T 1648-2019 Liquid Chromatography and Liquid Chromatography-Mass Spectrometry for Crow P Test in Suspected Drugs in Forensic Sciences
GA/T 1602-2019 Forensic sciences—Examination methods for diazepam and its metabolites in biological samples—LC and LC-MS
GA/T 1915-2021 Forensic sciences—Examination methods for hydrogen sulfide in biological samples—GC and GC-MS
GA/T 2038-2023 Forensic sciences-Examination methods for tramadol in suspecteddrugs-GC and CC-MS
GA/T 1622-2019 Forensic sciences—Examination methods for nereistoxin,bisultap,thiocyclam and cartap in biological samples—GC,GC-MS and LC-MS
GA/T 1614-2019 Forensic sciences—Examination methods for ketamine in biological samples—GC and GC-MS
GA/T 1929-2021 Forensic sciences-Examination methods for AB-CHMINACA, AB-FUBINACA and AB-PINACA in suspected drugs-LC and LC-MS
GA/T 1008.10-2013 GC and GC-MS examination methods for drugs—Part 10：Diazepam
GA/T 1008.11-2013 GC and GC-MS examination methods for drugs—Part 11:Bromazepam
GA/T 2037-2023 Forensic sciences-Examination methods for nimetazepam in suspected drugs-LC and LC-MS
GA/T 2043-2023 Forensic sciences-Examination methods for codeine in suspected cough syrup-GC and CC-MS
GA/T 2033-2023 Forensic Sciences-Examination methods for dihydroetorphine in suspected drug-LC and LC-MS
GA/T 1621-2019 Forensic sciences—Examination methods for buprofezin in biological samples—GC-MS and LC-MS
GA/T 2051-2023 Forensic sciences-Examination method for bromine in suspected precursor chemicals-GC and GC-MS
GA/T 1642-2019 Liquid Chromatography and Liquid Chromatography-Mass Spectrometry for Cannabis Detection in Forensic Science Suspected Drugs
GA/T 2044-2023 Forensic sciences-Examination methods for codeine in cough syrups-LC and LC-MS
GA/T 121-2019 Forensic sciences-Examination methods for cantharidin in biological samples-GC and GC-MS
GA/T 1329-2016 GC and GC-MS examination methods for ketamine in urine of drug user in forensic science
GA/T 1633-2019 Forensic sciences—Examination methods for ethyl glucuronide in blood and urine samples—GC-MS and LC-MS
GA/T 2030-2023 Forensic sciences-Examination methods for dolantin in suspected drugs-GC and GC-MS
GA/T 1603-2019 Forensic sciences—Examination methods for diphenidol in biological samples-GC and GC-MS
GA/T 1634-2019 Forensic sciences—Examination methods for four amphetamines including amphetamine in hair and blood samples—GC and GC-MS
GA/T 2036-2023 Forensic sciences-Examination methods for nimetazepam in suspected drugs-GC and GC-MS
GA/T 1617-2019 Forensic sciences—Examination methods for brucine and strychnine in biological samples—HPLC and LC-MS

Professional Standard - Agriculture

784兽药典二部-2015 Appendix Contents 0500 Chromatography 0521 Gas Chromatography
63药典四部-2020 0512 High performance liquid chromatography
85药典四部-2015 0521 Gas chromatography
202药典三部-2020 Chromatography 0512 High Performance Liquid Chromatography
792兽药典一部-2015 Appendix Contents 0500 Chromatography 0521 Gas Chromatography
183药典三部-2015 Chromatography 0512 General Principles of High Performance Liquid Chromatography 23
159药典三部-2010 Appendix III Chromatography IIIC Gas Chromatography
789兽药典一部-2015 Appendix Contents 0500 Chromatography 0512 High Performance Liquid Chromatography
186药典三部-2015 Chromatography 0521 General Principles of Gas Chromatography 27
82药典四部-2015 0512 High performance liquid chromatography
782兽药典二部-2015 Appendix Contents 0500 Chromatography 0512 High Performance Liquid Chromatography
66药典四部-2020 0521 Gas chromatography
2307药典二部-2010 Appendix V E Gas Chromatography
NY/T 1379-2007 Multi-residue Determination of 334 Pesticides in Vegetable by GC/MS and LC/MS
205药典三部-2020 Chromatography 0521 Gas Chromatography
158药典三部-2010 Appendix III Chromatography IIIB High Performance Liquid Chromatography
NY/T 3277-2018 Determination of 88 pesticides and their metabolites residues in water— Liquid chromatography-tandem mass spectrometry and gas chromatography-tandem mass spectrometry

Professional Standard - Commodity Inspection

SN/T 1859-2007 Determination of patulin and 5 - Hydroxymethylfurfural in beverage-LC-MS and GC-MS method
SN/T 4575-2016 Determination of multiple prohibited and restricted colorants in cosmetics for export-HPLC method and LC-MS/MS method
SN/T 5146-2019 Determination of L-carnitine in exported foods by high-performance liquid chromatography and liquid chromatography-mass spectrometry/mass spectrometry
SN/T 4252-2015 Determination of imidocarb residues in foodstuffs of animal origin for export - HPLC method and LC-MS/MS method
SN/T 2534-2010 Determination of Patulin in Fruit and Vegetable Products for Import and Export - LC-MS/MS and HPLC Method
SN/T 5878-2025 Determination of Benomyl Residues in Animal-derived Food for Export by Gas Chromatography and Gas Chromatography-Mass Spectrometry/Mass Spectrometry
SN/T 5113-2019 Determination of nitrofuran antibiotics in edible animals and feeds for import and export-LC-MS/MS method、LC method
SN/T 5112-2019 Determination of propylene glycol in edibe animals and feeds for import and export - GC Method and GC-MS method
SN/T 0654-2019 Determination of captan residues in fruits for Export GC and GC-MS/MS method
SN/T 4890-2017 Determination of curcuminoids in foodstuffs for export—HPLC method and HPLC-MS/MS method
SN/T 5732-2025 Determination of Fructooligosaccharides in Exported Liquid Milk by Liquid Chromatography and Liquid Chromatography-Mass Spectrometry/Mass Spectrometry
SN/T 2012-2019 Determination of benzoic acid and sorbic acid in vinegar for export-LC and I C-MS/MS method
SN/T 1971-2007 Determination of indoxacarb residues in food for import and export-GC and LC-MS/MS methods
SN/T 1974-2007 Determination of methylene bule residues in aquatic product for import and export LC-MS/MS and HPLC method
SN/T 4891-2017 Determination of Spirotetramat residue in foodstuffs for export—HPLC andLC-MS/MS method

Professional Standard - Machinery

JB/T 5225-1991 Standard Chromatographic Column for Testing of Gas Chromatograph
JB 5225-1991 Standard chromatographic column for gas chromatograph testing
JB/T 6857-1993 Liquid Chromatograph Test Method?
JB 6244-1992 Laboratory gas chromatograph
JB/T 6244-1992 Laboratory gas chromatograph
JB/T 5226-1991 Standard chromatographic column for testing of liquid chromatograph

Hebei Provincial Standard of the People's Republic of China

DB13/T 5097-2019 Gas Chromatography and Gas Chromatography-Mass Spectrometry Examination Method for 3-Fluoro-4-cyanophenol Ester Liquid Crystal Monomers

National Metrological Verification Regulations of the People's Republic of China

JJG 700-2016 Verification Regulation of Gas Chromatograph
JJG 705-1990 laboratory liquid chromatograph
JJG 705-2014 Verification regulation for liquid chromatographs
JJG 705-2002 Verification Regulation of Liquid Chromatographs

Group Standards of the People's Republic of China

T/EJCCCSE 065-2024 Preparative Liquid Chromatography System
T/DLQYLHH 007-2019 Preparation pump for liquid chromatography
T/NAIA 0299-2024 Water quality Determination of octachlorobiphenyl (PCB194) Liquid-liquid extraction/gas chromatography-mass spectrometry
T/CAIA YQ004-2018 Performance testing method for liquid chromatograph coupled with atomic fluorescence spectrometer
T/CRHA 060-2024 Detecting organic acids in urine—Gas chromatography-mass spectrometry method

Jiangsu Provincial Standard of the People's Republic of China

DB32/T 2203-2012 Determination of DEET and repellent in repellants by liquid chromatography and gas chromatography
DBS32/ 012-2016 High-performance liquid chromatography, liquid chromatography-mass spectrometry/mass spectrometry for the detection of quinoline yellow in local food safety standards

Agricultural Standard of the People's Republic of China

农业部1862号公告-2-2012 Determination of zolpidem in feeds.High performance liquid chromatography/Liquid chromatography-tandem mass spectrometry
农业部1730号公告-1-2012 Determination of eight benzimidazoles in feeds by liquid chromatography-tandem mass spectrometry method and high performance liquid chromatography method

Professional Standard - Petroleum

SY 5191-2011 Gas Chromatography Mud Logging Instrument
SY/T 5191-2011 Gas Chromatograph Mud Logging Unit

National Metrological Technical Specifications of the People's Republic of China

JJF 1317-2011 Calibration Specification for Liquid Chromatography-Mass Spectrometers
JJF(建材) 203-2023 Specification for calibration of micro gas chromatographic columns for portable gas chromatographs

Shandong Provincial Standard of the People's Republic of China

DB37/T 4942-2025 Water Quality - Determination of Decachloro diphenyl oxide - Liquid-Liquid Extraction / Gas Chromatography - Mass Spectrometry Method

Professional Standard - Energy

NB/SH/T 0230-2019 Determination of composition in Vquefied petroleum gases勿gas chromatography

Professional Standard - Education

JY/T 024-1996 General rules for high performance liquid chromatography

Chongqing Provincial Standard of the People's Republic of China

DB50/T 952-2019 Determination of Ochratoxin A in Animal Tissues by High Performance Liquid Chromatography and Liquid Chromatography Tandem Mass Spectrometry

GCC Standardization Organization

GSO ISO 12078:2014 Anhydrous milk fat -- Determination of sterol composition by gas liquid chromatography (Reference method)
GSO ISO 13859:2015 Soil quality -- Determination of polycyclic aromatic hydrocarbons (PAH) by gas chromatography (GC) and high performance liquid chromatography (HPLC)

British Standards Institution (BSI)

BS ISO 20163:2019 Vulcanized rubber. Determination of free sulfur by gas chromatography (GC) and high performance liquid chromatography (HPLC)
BS 3282:1963 Glossary of terms relating to gas chromatography
BS 7276:1990 Method for gas chromatographic analysis of liquefied petroleum gas
12/30231382 DC BS ISO 13859. Soil quality. Determination of polycyclic aromatic hydrocarbons (PAH) by gas chromatography (GC) and high performance liquid chromatography (HPLC)
BS EN ISO 21253-1:2019 Water quality. Multi-compound class methods - Criteria for the identification of target compounds by gas and liquid chromatography and mass spectrometry
BS PD ISO/TS 19046-1:2017 Cheese. Determination of propionic acid level by chromatography-Method by gas chromatography
20/30410986 DC BS EN 17503. Environmental solid matrices. Determination of polycyclic aromatic hydrocarbons (PAH) by gas chromatography (GC) and high performance liquid chromatography (HPLC)

The Directorate General of Specifications and Metrology (DGSM)

OS GSO ISO 13859:2015 Soil quality -- Determination of polycyclic aromatic hydrocarbons (PAH) by gas chromatography (GC) and high performance liquid chromatography (HPLC)

Japanese Industrial Standards Committee (JISC)

JIS K 0123:2006 General rules for gas chromatography/mass spectrometry
JIS K 8272:1972(1994) Liquid Chromatography Method for Analysis
JIS K 0123:2018 General rules for gas chromatography / mass spectrometry
JSA JIS K 0114-2012 General Rules for Gas Chromatography

International Organization for Standardization (ISO)

ISO 20163:2019 Vulcanized rubber — Determination of free sulfur by gas chromatography (GC) and high performance liquid chromatography (HPLC)

Danish Standards Foundation

DANSK DS/ISO 13859:2014 Soil quality - Determination of polycyclic aromatic hydrocarbons (PAH) by gas chromatography (GC) and high performance liquid chromatography (HPLC)
DANSK DS/ISO 21253-1:2019 Water quality – Multi-compound class methods – Part 1: Criteria for the identification of target compounds by gas and liquid chromatography and mass spectrometry

Swedish Institute for Standards

SS-EN 14331:2004 Liquid petroleum products - Separation and characterisation of fatty acid methyl esters (FAME) from middle distillates - Liquid chromatography (LC)/gas chromatography (GC) method
SS-EN 17411:2020 Fertilizers - Determination of perchlorate in mineral fertilizers by liquid chromatography and tandem mass spectrometry detection (LC-MS/MS)
SS-EN 12393-2:2013 Foods of plant origin - Multiresidue methods for the determination of pesticide residues by GC or LC-MS/MS - Part 2: Methods for extraction and clean-up
SS-EN 12393-1:2013 Foods of plant origin - Multiresidue methods for the determination of pesticide residues by GC or LC-MS/MS - Part 1: General considerations

Korean Agency for Technology and Standards (KATS)

KS M 6905-2021 Leather — Determination of the perfluorinated compounds(PFCs) by gas chromatography-tandem mass spectrometry(GC-MS/MS) and liquid chromatography-tandem mass spectrometry(LC-MS/MS)
KS M 0031-1999 General rules for gas chromatographic analysis
KS M 0031-2017(2022) General rules for gas chromatographic analysis
KS M 0027-2008(2023) General rules for analytical methods in gas chromatography mass spectrometry
KS M 0027-2023 General rules for analytical methods in gas chromatography mass spectrometry
KS M 0027-1993 General Rules for Analytical Methods in Gas Chromatography Mass Spectrometry

Clinical and Laboratory Standards Institute

CLSI C62-A-2014 Liquid Chromatography Mass Spectrometry Method Approval Guide

Association Francaise de Normalisation

NF X43-025:1988 Air quality. Ambient air. Determination of polycyclic aromatic hydrocarbons. High pressure liquid chromatography and gaz chromatography determination.

American Society for Testing and Materials (ASTM)

ASTM DS25A-1967 Gas Chromatography Data Compilation

CN-STDBOOK

图书 3-8314 ATC 011 Liquid Chromatography Analysis Technique

German Institute for Standardization

DIN EN ISO 21253-1:2022-12 Water quality - Multi-compound class methods - Part 1: Criteria for the identification of target compounds by gas and liquid chromatography and mass spectrometry (ISO 21253-1:2019); German version EN ISO 21253-1:2019

Gosstandart of Russia

GOST R EN 14331-2010 Liquid petroleum products. Separation and characterization of fatty acid methyl esters (FAME) from middle distillates by method of liquid chromatography and gas chromatography

Society of Automotive Engineers (SAE)

SAE J1151_198806 Methane Measurement Using Gas Chromatography