Preparation method of heavy metal-containing crayon standard sample for laboratory capability verification

Abstract

The present invention discloses a heavy metal-containing crayon standard sample for laboratory capability verification, a preparation method and applications thereof. According to the heavy metal-containing crayon standard sample for laboratory capability verification, relative deviation of detection results does not exceed 15%, standard deviation of sample nonuniformity is not more than 0.3sigma, sample uniformity and stability meet capability verification sample requirements, the blank that the class of the capability verification samples do not exists in our country is filled, and a detection level of a laboratory participating in capability verification is increased.

Description

Technical field: [0001] The invention relates to a method for preparing a heavy metal-containing crayon standard sample used in laboratory proficiency verification. Background technique: [0002] At present, as the international community pays more and more attention to the safety of consumer products, the detection of harmful chemical substances in toys and other consumer products is increasing. In addition to traditional heavy metals, plasticizers, azo, bisphenol A, organotin compounds, etc. are strictly restricted Correspondingly, the chemical testing items and testing laboratories of consumer goods are increasing continuously. Taking toy product testing as an example, the chemical testing workload accounts for as high as 80% of the total project testing, and there are nearly 200 toy professional testing laboratories accredited by CNAS; at the same time , proficiency testing is becoming increasingly important for the quality control of the laboratory itself and the manage...

AI Technical Summary

Problems solved by technology

GB6675-2003 transferable heavy metal test includes various types of materials. In the past, the proficiency testing plan for toy transferable heavy metal testing carried out by CNAS mainly focused on paint coating materials, and less involved materials such as crayons. However, due to the detection methods of different materials in the sample There is a big difference in the pre-treatment. The test of the content of migratable heavy metals in crayons is more complicated than that of paint in terms of sample pre-treatment. A wax removal step is added before extraction, and the extraction steps are also different, which increases the uncertainty of the test results.

[0004] In addition, because crayons are generally melted into wax liquid at high temperature and then solidified into a solid, and the toner cannot be dissolved in the wax liquid, it is difficult to mix paraffin with heavy metal toner evenly, so it is difficult to obtain a uniform and stable crayon sample

[0005] At present, among the crayon samples containing heavy metals actually detected, very few crayons containing heavy metals are detected or the test results are positive, and the uniformity of these samples is difficult to meet the requirements of proficiency testing

[0006] In summary, there is no crayon standard sample containing heavy metals and its preparation method for laboratory proficiency testing.

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