Gas Chromatography Application Example Analysis

(a) Determination of residual solvents in vegetable oils:

According to the national standard GB/T5009.37-2003 headspace gas chromatography on the 6th solvent residue in leach oil determination. A hydrogen flame ionization detector was used and a packed column coated with a 5% DEGS fixative was installed. The standard curve of the external standard method was used for quantification. It is also possible to use the DJ-200 headspace sampler (6 headspace bottles can be placed, headspace bottle size: 2, 10, 20 ml optional). The use of a headspace sampler ensures the reliability of the analysis and improves the efficiency of the analysis. The heated, airtight needle cover ensures that the sample is not diluted and has no condensation.

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

Using hydrogen flame ionization detectors, using 20% ​​DNP 7% Tween-80, or Lanzhou Institute of Technology, large-diameter ¢0.53mm capillary column to complete the main alcohols, aldehydes, acids in Luzhou-flavor liquor and fragrance-flavor liquors. Analysis of individual ester components. The use of capillary columns, in addition to increased 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.

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

Using hydrogen flame ionization detector and thermal conductivity detector, Ni catalyst converter, six-way valve automatic switching, no secondary flow separation system, automatic analysis of transformer oil cracking products (8 kinds of component gases) once sample injection , Quantitative accuracy, high sensitivity. Microcomputer control can automatically switch the output signal of FID/TCD.

The sampling method of oscillating degassing can be used, and the automatic headspace sampler can also be used to automatically sample. The analysis results are in full compliance with the national standard GB7252-2001.

(d) Indoor air detection analysis:

The hydrogen flame ionization detector is used, together with a thermal desorption sampler, packed column or capillary column, and a dedicated column can be used according to GB50325-2001 to complete benzene, toluene, xylene and total volatile organics in indoor air. Compound (TVOC) detection. Derivatized gas chromatography, derivatization with 2.4-dinitrophenylhydrazine, extraction with cyclohexane, separation with OV-17 and QF-1 mixed chromatographic column, determination of formaldehyde in indoor air using electron capture detector (ECD) Compared with the determination of formaldehyde by colorimetry, it has the advantages of sensitivity, accuracy, no interference, and easy preservation of reagents.

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

The use of TCD, FID, together with a dedicated column can complete the detection of moisture and nicotine content in the total flue gas phase of flue gas. The method is a rapid, accurate, and advanced test method commonly used in the world. Determination of organochlorine, organophosphorus, pyrethroids, and other pesticide residues in tobacco and tobacco products can be accomplished using ECD, FPD, and NPD detectors with different capillary columns. Refer to national standard GB/T13595-2004 and GB/T13596-2004.

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

Different kinds of detectors and columns can be used to complete sorbic acid, benzoic acid in foods (GB/T5009.29-2003), residual organophosphorus pesticides in foods (GB/T5009.20-2003), and foods in 666 , Residues of DDT (GB/T5009.19-2003), Carbamate pesticide residues in foods (GB/T5009.145-2003 and GB/T5009.104-2003), Pyrethroid pesticide residues in food, for plants Sex food (GB/T5009.110-2003) and animal food (GB/T5009.162-2003). Gas Chromatography of Polychlorinated Biphenyls in Seafood (GB/T5009.190-2003). The chloropropanol test in foods can be determined using trichloroacetic anhydride derivatization combined with an electron capture detector (ECD). According to GB/T14551-93, the use of an electron capture detector, combined with a capillary sampling system and a dedicated large-diameter capillary column, can be used to detect organochlorine pesticide residues in tea.