Gas chromatograph application areas and related analysis examples

First, the application area:

1. Petroleum and petrochemical analysis:

Chemical analysis, crude oil analysis, refinery gas analysis, simulated distillation, oil analysis, elemental hydrocarbon analysis, sulfur/nitrogen/oxygenate analysis, gasoline additive analysis, aliphatic hydrocarbon analysis, and aromatics analysis in oil and gas field exploration.

2. Environmental analysis:

Air pollutant analysis, water analysis, soil analysis, solid waste analysis.

3. Food analysis:

Pesticide residue analysis, flavor and fragrance analysis, additive analysis, fatty acid methyl ester analysis, food packaging material analysis.

4. Drug and clinical analysis:

Analysis of estriol, analysis of catecholamine metabolites, analysis of gestational diol and gestrinol in urine, analysis of testosterone in plasma, analysis of ethanol/anesthetic agents and amino acid derivatives in blood.

5. Analysis of pesticide residues:

Analysis of organochlorine pesticide residues, organophosphorus pesticide residue analysis, pesticide residue analysis, herbicide residue analysis, etc.

6. Fine chemical analysis:

Additive analysis, catalyst analysis, raw material analysis, product quality control.

7. Polymer analysis:

Monomer analysis, additive analysis, copolymer composition analysis, polymer structure characterization / impurity analysis in polymers, thermal stability studies.

8. Synthetic industry:

Methodological research, quality monitoring, process analysis.

Second, analysis examples:

(1) Natural gas constant analysis:

Constant conductivity detector for constants of natural gas O ₂ , N ₂ , CH ₄ , CO ₂ , C ₂ H ₆ , C ₃ H ₈ , iC ₄₀ , nC ₄₀ , iC ₅₀ , nC ₅₀ analysis. The analysis results are in line with the national standard GB10410.2-89.

(2) Analysis of artificial gas:

Use thermal conductivity detector, double valve multi-column system, automatic or manual injection, suitable for H ₂ , O ₂ , N ₂ , CO ₂ , CH ₄ , C ₂ H ₄ , C ₂ H ₆ , C ₃ in artificial gas Determination of main components such as H ₆ . The analysis results are in line with the national standard GB10410.1-89.

(III) Analysis of LPG 1:

Use thermal conductivity detector, packed column system, automatic or manual switching of valves, and equipped with backflushing system for analysis of C2-C4 and total C5 hydrocarbon composition in liquefied petroleum gas produced by refineries (excluding diolefins and Alkyne). The analysis results are in accordance with SH/T10230-92.

Liquefied petroleum gas analysis 2:

Use thermal conductivity detector, packed column system, valve automatic or manual switching, and equipped with backflush

System for the analysis of gaseous hydrocarbon components below C5 in liquefied petroleum gas (excluding alkynes). The analysis results are in accordance with GB10410.3-89.

(4) Analysis of refinery gas:

The thermal conductivity and hydrogen flame ionization detector are selected, the packed column and the capillary column are separated, the multi-valve is automatically switched, the signal is automatically switched, and one injection is performed, multi-dimensional chromatography is analyzed, and H ₂ , O ₂ , N ₂ , CO _{2 are} quickly analyzed. , CO, C ₁₀ -C ₆₀ , C ₂ -C ₄ and C ₆ or more hydrocarbon components. The analysis results are reproducible and easy to operate, and can be compared with imported instruments.

(5) Analysis of benzene and toluene in motor and aviation gasoline:

The thermal conductivity detector or the hydrogen flame ionization detector is selected, the double column is connected in series, the valve is automatically switched, and the backflushing system is equipped to realize the qualitative and quantitative analysis of benzene and toluene in gasoline by one injection. The analysis results are in line with the national standard GB17930-1999.

(6) Analysis of certain alcohols and ethers in gasoline:

The hydrogen flame ionization detector, multi-column system, ten-way valve automatic switching and backflushing are used to analyze certain alcohols and ethers in gasoline. It is especially suitable for the analysis of alcohols and ethers in automotive and aviation gasoline and ethanol-containing gasoline. See ministerial standard SH/T0663-1998.

(7) Gas chromatographic analysis of the hygienic standard of distilled liquor and prepared wine:

A hydrogen flame ionization detector, a GDX-102 packed column or a FFAP large-diameter capillary column was used, and the external standard method (peak area) was used to quantify the methanol and fusel oil in the liquor. The analysis results are in full compliance with the national standard GB/T.5009.48-2003.

(8) Alcohol for food:

The PEG-20M capillary column was used to detect the trace components such as methanol and fusel oil in high quality edible alcohol by FID detector and internal standard method. The analysis results are in full compliance with the requirements of national standard GB10343-2002.

(9) Analysis of aldehydes, alcohols and esters in liquor:

Using hydrogen flame ionization detector, using 20% ​​DNP + 7% Tween-80, or Lanzhou Chemical Institute large diameter ¢ 0.53mm dedicated capillary column, complete the main alcohol, aldehyde, acid in Luzhou-flavor liquor and fragrant liquor Analysis of the individual components of the ester. The use of capillary columns in addition to improved analytical efficiency can also detect organic acids, providing more valuable information for complex brewing fermentation processes. The analysis results are in full compliance with the national standard GB10345.7-89/GB10345.8-89.

(10) Detection of residual solvents in vegetable oil:

The residual amount of solvent No. 6 in the leaching oil can be determined according to the national standard GB/T5009.37-2003 headspace gas chromatography. A hydrogen flame ionization detector was used, and a packed column coated with 5% DEGS fixative was packed, and the external standard method was used to quantify the standard curve. You can also use the DJ-200 headspace sampler (you can place 6 headspace bottles, headspace bottle specifications: 2, 10, 20ml optional). The use of a headspace sampler ensures analytical reliability and improved analytical efficiency. The heated gas tight needle sleeve ensures that the sample is not diluted or condensed.

(11) Analysis of indoor air detection:

The hydrogen flame ionization detector is selected, coupled with a thermal desorption sampler, a packed column or a capillary column. The special chromatographic column can be selected according to the national standard GB50325-2001 to complete benzene, toluene, xylene and total volatile organic compounds in indoor air. Detection of Compound (TVOC). Derivatization by gas chromatography, derivatization with 2.4-dinitrophenylhydrazine, extraction with cyclohexane, separation by OV-17 and QF-1 mixed-coating column, determination of formaldehyde in indoor air by electron capture detector (ECD) Compared with the determination of formaldehyde by colorimetry, it has the advantages of sensitivity, accuracy, no interference, easy storage of reagents and the like.

(12) Gas chromatographic analysis of transformer oil cracking products:

The hydrogen flame ionization detector and the thermal conductivity detector are used, the Ni catalyst converter and the six-way valve are automatically switched, and the secondary shunt system is not used, so that the transformer oil cracking product (8 component gases) is automatically injected in one injection. , accurate and high sensitivity. Microcomputer control can automatically switch the output signal of FID/TCD. The sampling method of oscillating degassing can be used, or the automatic injection of the automatic headspace sampler can be used. The analysis results are in full compliance with the national standard GB7252-2001.

(13) Analysis of pesticide residues in food additives and foods:

Different types of detectors and columns can be used to complete sorbic acid and benzoic acid in food (GB/T5009.29-2003), organophosphorus pesticide residues in food (GB/T5009.20-2003), and food sixty-six six , DDT residue (GB/T5009.19-2003), carbamate pesticide residues in food (GB/T5009.145-2003 and GB/T5009.104-2003), pyrethroid pesticide residues in food, used in plants Sex food (GB/T5009.110-2003) and animal food (GB/T5009.162-2003). Gas chromatography of polychlorinated biphenyls in marine products (GB/T5009.190-2003). The test for chloropropanol in food can be determined by trichloroacetic anhydride derivatization combined with an electron capture detector (ECD). With reference to GB/T14551-93, an electron capture detector, with a capillary injection system and a dedicated large-diameter capillary column, can be used to detect organochlorine pesticide residues in tea.

(14) Detection and analysis of tobacco and tobacco products:

TCD, FID and special column can be used to detect the moisture and nicotine content in the total particulate phase. The method is a fast, accurate and advanced test method commonly used in the world. For the determination of pesticide residues such as organochlorine, organophosphorus and pyrethroid in tobacco and tobacco products, ECD, FPD and NPD detectors can be used with different capillary columns. Refer to GB/T13595-2004 and GB/T13596-2004.

(15) Others:

In addition to the above analysis, the determination of the ethanol content in the blood and the analysis of the residual solvent in the drug can be completed with the static headspace sampling device. Odor analysis in foods can be achieved using solid phase micro-extraction devices and headspace technology. The analysis of volatile aromatics in wastewater and the analysis of volatile organic compounds in drinking water were carried out using a purge-capture injection technique. PTV-GC/ECD and NPD simultaneously measure the chromatographic analysis of various pesticide residues in environmental water.

Gas Chromatograph Application:

1. Determination of volatile organic matter in water (drinks): waterworks, beverage plants, technical supervision bureaus (stations), etc.

2. Indoor Air Pollutant Detection (TVOC): environment, air testing department, quality inspection station, real estate agent, etc.

3. Transformer oil analysis: chemical plant, petrochemical plant, refinery, power sector, technical supervision department, etc.

4. High purity gas analysis: liquefier plant, natural gas plant, gas company, hydrogen production plant, gas station, etc.

5. Detection of residual solvents in medicines: testing of pesticide residues in hospitals, quality inspection, safety and security departments, and vegetables

6. Determination of residual ethylene oxide in medical equipment: identification agencies, hospitals, etc.

7. Analysis of the ingredients of liquor flavor: winery, food factory, liquor production plant, technical supervision department

8. Detection of alcohol content in blood (detection of alcohol content in blood): hospital, transportation department, testing institution

9. Natural gas analysis

10. Melamine detection

11. Packaging residue analysis