大气PM_(2.5)中汞及其他19种元素的L-半胱氨酸直接加入-超声混酸提取-电感耦合等离子体质谱同时测定法  

Simultaneous determination of mercury and other 19 elements in ambient PM_(2.5)by ICP/MS with L-Cysteine direct addition after ultrasonic mixed acid extraction

作　　者：陈翔[1] 倪蓉[1] 梁卫玖 CHEN Xiang;NI Rong;LIANG Wei-jiu(Department of Physical and Chemical,Xuhui Centre for Disease Control and Prevention,Shanghai,200237,China;Department of Physical and Chemical,Changning Centre for Disease Control and Prevention,Shanghai,200051,China)

机构地区：[1]上海市徐汇区疾病预防控制中心理化科,上海200237 [2]上海市长宁区疾病预防控制中心理化科,上海200051

出　　处：《职业与健康》2023年第5期613-619,共7页Occupation and Health

摘　　要：目的建立L-半胱氨酸(L-Cysteine,L-Cys)直接加入-超声混酸提取-电感耦合等离子质谱(inductively coupled plasma mass spectrometry,ICP/MS)法同时测定大气细颗粒物(fine particulate matter,PM_(2.5))中汞和铍、铝、钒、铬、锰、钴、镍、铜、砷、硒、钼、银、钡、锑、镉、铊、铅、钍、铀等元素的方法。方法PM_(2.5)采样滤膜以含0.025%L-Cys的2%盐酸和5%硝酸的混酸为提取液于70℃超声提取3 h,以含0.01%L-Cys的0.8%盐酸和2%硝酸的混酸将汞和其他19种元素配制成混合标准系列,以ICP/MS氦碰撞模式同时测定样品中汞及其他19种元素。结果L-Cys及盐酸在样品提取液中最合适浓度分别为0.025%及2%,当采样体积为1056 m^(3)时,20种元素的方法检出限在0.004~2.152 ng/m^(3)之间,r值均>0.9994,不同浓度水平的加标回收率在89.6%~105.3%,相对标准偏差(relative standard deviation,RSD)均小于3.2%。结论将L-Cys直接加入标准和样品中有效消除了汞的记忆效应,在提取液中加入盐酸提高了锑及银的稳定性,应用动能歧视模式(Kinetic energy discrimination,KED)消除了因盐酸引入的多原子离子干扰,汞和其他元素标准系列混配提高了工作效率,该法适用于PM_(2.5)样品中汞及多种元素的同时测定。Objective To establish a method for simultaneous determination of Hg and Be,Al,V,Cr,Mn,Co,Ni,Cu,As,Se,Mo,Ag,Ba,Sb,Cd,Tl,Pb,Th,U in ambient PM_(2.5)by ICP/MS with L-cysteine direct addition after ultrasonic mixed acid extraction.Methods The sampling quartz membrane filters of PM_(2.5)were extracted at 70℃ by ultrasonic cleaner for 3 hours with a mixed acid consisted of 2%hydrochloric acid and 5%nitric acid with 0.025%L-Cysteine.Mercury and other 19 elements were prepared into a mixed calibration series with a mixed acid consisted of 0.8%hydrochloric acid and 2%nitric acid with 0.01%L-Cysteine.The mercury and other 19 elements of the samples were determined in helium collision mode by ICP/MS simultaneously.Results The most suitable concentrations of L-cysteine and hydrochloric acid in the sample extract were 0.025%and 2%respectively.When the sampling volume was 1056 m^(3),the method detection limits of 20 elements were within 0.004-2.152 ng/m^(3) and the correlation coefficients were all greater than 0.9994.The recoveries of spiked quartz membrane filters at different concentration levels were between 89.6%and 105.3%,with the relative standard deviation(RSD)all less than 3.2%.Conclusions Adding L-cysteine directly to standards and samples eliminates the memory effect of mercury effectively.Adding hydrochloric acid to the extract improves the stability of antimony and silver.The application of Kinetic energy discrimination(KED)mode eliminates the interference of polyatomic ions introduced by hydrochloric acid,and the mixing of mercury and other elements to formulate the calibration series improves the working efficiency.This method is suitable for simultaneous determination of mercury and multiple elements in PM_(2.5)samples.

关 键 词：L-半胱氨酸 超声提取 电感耦合等离子体质谱法 细颗粒物 

分 类 号：R115[医药卫生—公共卫生与预防医学]