ICP-MS测定大气细颗粒物中多种金属元素方法的研究与应用

Research and application of multiple metal elements in atmospheric fine particulate matter measured by ICP-MS

目的 建立电感耦合等离子体质谱仪法(ICP-MS)同时测定大气细颗粒物(PM_(2.5))中锑(Sb)、铝(Al)、砷(As)、铍(Be)、镉(Cd)、铬(Cr)、铅(Pb)、锰(Mn)、镍(Ni)、硒(Se)和铊(Tl)共11种金属元素含量,并用于城市大气PM_(2.5)中金属污染特征分析。方法 3种不同材质的颗粒物采样滤膜分别采用3种酸体系经微波消解、超声浸提2种方法进行处理,确定最佳的采集滤膜和前处理方式,监测连续7 d采集滤膜中的金属含量,考察采集样品冷藏3个月后的稳定性。结果 11种元素在各自的浓度范围内线性良好,相关系数(r)均≥0.999 6,方法检出限(LOD)为0.005~1.0 ng/m^(3),加标回收率为81.2%~117.0%,相对标准偏差为0.58%~4.27%。实际样品检测结果表明,除Be外,芜湖市主城区PM2.5中检出10种金属,其中Al、Pb、Mn检出浓度含量之和占11种金属总量的87.3%,且占比排序为Al>Mn>Pb。结论 超声浸渍-电感耦合等离子体质谱法操作简单易推广,灵敏度高,稳定性好,该方法适应于大气PM_(2.5)中多种金属同时测定。

Objective To establish an inductively coupled plasma mass spectrometry(ICP-MS)method for simultaneous determination of 11 metal elements in atmospheric fine particulate matter(PM_(2.5)),i.e.antimony(Sb),aluminum(Al),ar-senic(As),beryllium(Be),cadmium(Cd),chromium(Cr),lead(Pb),manganese(Mn),nickel(Ni),selenium(Se),and thallium(Tl),and to investigate the value of this method in analyzing the pollution characteristics of metal elements in ur-ban atmospheric PM_(2.5).Methods Three kinds of particulate sampling filter membranes made from different materials were treated by microwave digestion and ultrasonic extraction to determine the best filter membrane and method,and the stability of metal elements in the sampling filter membrane refrigerated for three months was investigated.Results All 11 elements showed a good linear relationship within their respective concentration range with a linear correlation coefficient of≥0.9996,the limit of detection was 0.005-1.0 ng/m^(3) for this method,and the recovery rate was 81.2%-117.0%,with a relative standard deviation of 0.58%-4.27%.Determination of the samples showed that except Be,all the other 10 metals were detected in PM 2.5 in the main urban area of Wuhu,among which the total concentration of Al,Pb,and Mn accounted for 87.3% and Al had the highest concentration,followed by Mn and Pb.Conclusion Ultrasonic impregnation-ICP-MS is simple and easy to promote,with high sensitivity and good stability,and this method can be used for the simultaneous deter-mination of multiple metals in PM_(2.5).