Liquid nitrogen pulverization-gas chromatography method for detecting harmful substances of acrylonitrile, styrene and ethylbenzene in packaging materials

Abstract

The invention belongs to the field of packaging material analysis and detection, and in particular, relates to a method for detecting harmful substances of acrylonitrile, styrene and ethylbenzene in a packaging material by liquid nitrogen pulverization-gas chromatography. The method comprises the following steps: cutting a sample into small particles, cooling by liquid nitrogen, placing in a liquid nitrogen pulverization instrument, and pulverizing; and weighing a certain amount of crushed sample, placing in a headspace bottle, quickly sealing, setting the proper heating temperature and heating time, and carrying out gas chromatographic analysis of the harmful substances in the sample. According to the standard sample peak appearance time and appearance peak size, acrylonitrile, styrene and ethylbenzene in the packaging material are qualitatively and quantitatively analyzed; in the established method, the detection limit of acrylonitrile is 0.1 mg / kg, and the detection limits of styrene and ethylbenzene are both 0.2 mg / kg. The method is simple and convenient to operate, the result is stable and reliable, and the harmful substances in the sample can be qualitatively and quantitatively detected quickly. Compared with a conventional sample solvent-dissolution method, the method saves the sample pretreatment time, reduces the detection limits of the harmful substances, and has good promotion and application value.

Description

technical field [0001] The invention relates to a method for detecting harmful substances of acrylonitrile, styrene and ethylbenzene in food packaging materials, in particular to a liquid nitrogen pulverization-gas chromatography detection of acrylonitrile, styrene and ethylbenzene in plastic packaging materials AS and ABS method. Background technique [0002] Acrylonitrile-styrene copolymer (AS) and acrylonitrile-butadiene-styrene copolymer (ABS), as thermoplastic engineering plastics, have the characteristics of heat resistance, oil resistance, chemical corrosion resistance and high impact strength, and are widely used in food Containers, food processing machinery and equipment, such as food contact materials such as water cups, beverage cups, juicers, soybean milk makers, etc. [0003] The harmful monomers remaining in AS and ABS materials mainly include acrylonitrile, ethylbenzene and styrene. As early as the 1980s, the U.S. Consumer Product Safety Commission found tha...

AI Technical Summary

Problems solved by technology

At present, the detection method of acrylonitrile in the national standard is mainly GB / T 5009.152-2003 "Styrene-acrylonitrile copolymer and rubber-modified acrylonitrile-butadiene-styrene resin for food packaging and residual acrylonitrile in its molded products "Determination of Monomer", the sample in the standard is dissolved in N, N-dimethylformamide, and the method of packed column-manual headspace is used for detection. In actual detection, this method has certain defects: (1) N , N-dimethylformamide is a high boiling point reagent, which is an ideal solvent in gas phase detection, but its dissolving ability in dissolving AS and ABS materials is limited, and some materials are often not completely dissolved after ultrasonic dissolution for 30 minutes, which affects Determination effect; (2) The standard stipulates to add 3mLN, N-dimethylformyl to dissolve the sample and perform headspace operation. Due to the large solvent content, the proportion of solvent after headspace heating is relatively large, and the proportion of harmful substances in the sample The specific gravity is small, resulting in a low detection limit of the method

Images