Determination of eight plasticizers Nb in PVC by f

2022-09-22
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Determination of eight plasticizers in PVC by gas chromatography nbsp

phthalates have been widely used in plastic products as plasticizers and cold resistant agents, but their carcinogenicity has also attracted increasing attention. Therefore, it is necessary to analyze and study the content of plasticizer. The residues of dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), benzyl butyl phthalate (BBP), bis (2 ethylhexyl) phthalate (DEHP), diisopropyl phthalate (DINP), di-n-octyl phthalate (DnOP), diisopropyl phthalate (DIDP) and other eight phthalates in polyvinyl chloride (PVC) materials were determined by gas chromatography (GC). The method is simple, rapid and sensitive

1 experimental part

1.1 instruments and reagents

Nanjing Kejie gas chromatograph gc5890f, equipped with hydrogen flame ionization detector (FID)

dichloromethane: analytically pure. Phthalate reference material

1.2 chromatographic analysis conditions

special chromatographic column; Programmed temperature rise: 80 ℃ 20 ℃/min200 ℃ 5 ℃/current min220 ℃ (1min) 20 ℃/min300 ℃ (3min). Detector temperature: 340 ℃, sample inlet temperature: 320 ℃; Gas pressure: N2 total pressure 260kpa, carrier gas N2 pressure 180kpa, H2 pressure 65kpa, air pressure 55kpa; Purging flow of spacer: 5~10ml/min; Shunt gas flow: 50~100ml/min; Injection volume: 1 μ L。

1.3 preparation of standard solution

use dichloromethane to prepare phthalate ester into a mixed standard stock solution with a mass concentration of 5g/l. When using, dilute it with dichloromethane as needed to form a series of standard working solutions with a mass concentration (0.005,0.01,0.05,0.1,0.5g/l). Another group of mixed solution containing DINP and DIDP only, with a mass concentration of 0.05,0.1 mechanical testing equipment, 0.5,1,2g/l

1.4 sample preparation

cut the PVC material into 2~3mm long debris, accurately weigh 1.0000g, use dichloromethane as solvent, extract the phthalate with Soxhlet extractor, and fix the volume of the extract to 25ml with dichloromethane after 2H. Analyze with capillary gas chromatograph and gas chromatography-mass spectrometry, qualitative according to retention time and mass spectrum, quantitative with gas chromatography external standard method, in which DINP and DIDP are semi quantitative with peak group area integration method or quantitative with peak area of respective characteristic ions

2 results and discussion

2.1 standard chromatogram

according to the analysis conditions that there is no complete wire in the above sub equipment, the mixed standard solution with the mass concentration of 8 plasticizers of 0.5g/l is analyzed, and the chromatograms of 8 plasticizers obtained

2.2 qualitative analysis

pose new challenges to material design; The trunk of the autonomous vehicle determines the existence of each component of the plasticizer by comparing the retention time of the chromatographic peak of the sample to be tested with the retention time of the calibration standard sample. In order to ensure the accuracy of the identification of each component peak, the suspected component peak can be judged by adding a mark

2.3 quantitative analysis

the external standard method is used to quantify according to the linear relationship between the peak area and the mass concentration of phthalates. (omitted)

2.4 sample determination

according to the method established in this paper, it is found that DINP and DIDP commonly exist in PVC materials, and the content of other components is very small. Occasionally, DMP or dep is false positive. The following heating up procedure can be adopted: 80 ℃ 10 ℃/min200 ℃ 20 ℃/min300 ℃ (3min) measure the samples and spiked samples respectively, and correct the standard to determine the authenticity of the positive. For DINP and DIDP, semi quantitative analysis can be achieved by using peak group integration and increasing the sensitivity by 10 times

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