热熔型路面标线涂料重金属检测方法

Detection Method of Heavy Metal in Hot-melt Road Marking Paint

热熔型路面标线涂料用量巨大,其中重金属对环境造成很大污染.国内刚出台对其重金属等有害物质限量和检测方法的标准,但其中的重金属检测方法仍有改善的空间.该文建立了区别于标准的热熔型路面标线涂料重金属检测方法.首先采用正交试验,确定了热熔型路面标线涂料中硝酸、氢氟酸、过氧化氢相结合的消解体系;其次采用火焰原子吸收光谱法对铬、镉、铅、锑4种重金属进行检测,并优化燃助比(乙炔流量/空气流量)、燃烧头高度2个参数;最后采用氢化物发生原子吸收法对砷、汞进行检测,优化了酸质量分数、还原剂质量浓度、泵吸时间3个参数. 6种重金属元素的加标回收率为91.1%~109.2%,检出限分别为:0.011 mg/L、0.052 mg/L、0.025 mg/L、0.033 mg/L、0.272μg/L、0.223μg/L,结果表明该方法适用于热熔型路面标线涂料的有害物质检测.

The amount of hot-melt pavement marking paint is huge,among which heavy metals cause great pollution to the environment.China has just issued the standards for the limits and detection methods of harmful substances such as heavy metals,but there is still room for improvement in the detection methods of heavy metals.The detection method of heavy metals in hot-melt pavement marking coating was established,which was different from the standard.First,the digestion system of nitric acid,hydrofluoric acid and hydrogen peroxide in hot-melt pavement marking coating was determined by orthogonal test.Second,four kinds of heavy metals(Cr,Cd,Pb,and Sb) were detected by FAAS.Two parameters of fuel assist ratio(acetylene flow/air flow) and combustion head height were optimized.Finally,hydride generation atomic absorption spectrometry was used to detect arsenic and mercury.Three parameters of acid concentration,reducing agent concentration and pumping time were optimized.The recoveries of six heavy metals were 91.1% to 109.2%,and the detection limits were 0.011 mg/L,0.052 mg/L,0.025 mg/L,0.033 mg/L,0.272 μg/L,and 0.223 μg/L,respectively.Results show that the method is suitable for the detection of harmful substances in hot-melt pavement marking paint.