[Determination of copper, chromium and arsenic in wood and its products by high pressure digest-ICP-AES].

Sample preparation was studied, samples were sawn to be sawdust, screened by a 35 mesh sieve, dryed 4-5 h at 105 degrees C, and its homogeneity was tested by variance analysis. Sample pretreatment methods were investigated with wet decomposition, dry ashing, high pressure digest (including microwave-assisted closed digestion and steel liner PTFE vessel digestion). According to the comparative results, wet decomposition is fit for testing soluble copper, chromium and arsenic. Dry ashing and high pressure digest are fit for testing total copper, chromium and arsenic, but arsenic is easy to lose in dry ashing. Acidity effect and matrix effect were discussed. A method was proposed for the determination of total copper, chromium and arsenic in wood and its products by high pressure digest-ICP-AES. The detection limit of copper, chromium and arsenic was 1.2, 0.2 and 7.1 mg x kg(-1), respectively, RSDs were in the range of 0.2%-1.5%, and recoveries were between 92% and 106%. Using this method, more reasonable results will be given for controlling toxic substances from wood and its products and their wastes. This method has been applied to practical sample analysis.

[Determination of soluble heavy metal Pb, Cd and Cr in water based architectural coatings for indoor decorating and refurbishing materials by ICP-AES].

In this paper the authors have studied coexisting element interference and acidity effect in sample, corrected spectral overlapping interference and non-spectral interference by interference coefficient method and standard addition method respectively, and established a method for the determination of soluble heavy metal Pb, Cd and Cr in water based architectural coatings by ICP-AES. The method is accurate and of low detection limit, and can be applied to the inspection work of water based architectural coatings.

[PCR detection of transgenic elements in feed raw material].

Based on the heterogeneous genes usually used in transgenic crops, the PCR technique was performed with primers derived from CaMV 35S promoter (35S-promoter,originated from cauliflower mosaic virus), NOS terminator (nopaline synthase-terminator,derived from Agrobacterium tumefaciens), EPSPS (5-enolpyruvylshikimate-3-phosphate synthase) gene, and CryIA(b) (delta-endotoxin,evolved from Bacillus thuringiensis subsp. kurstaki) gene to detect transgenic agents from feed raw materials of soybean dregs and corn gluten meal, respectively. Endogenous corn Zein (a protein extracted from corn gluten) gene, soybean Lectin (chitin-binding protein) gene and negative, positive control were applied for avoiding false results. The method established here has been successfully applied in detecting transgenic elements in imported feed raw material.