摘要
在单因素试验基础上,采用Plackett-Burman设计和中心组合设计试验筛选和优化了提取剂用量、超声时间和超声温度等条件对超声辅助提取PM_(2.5)中Pb的影响.实验结果表明:在最佳提取条件下,即提取温度95℃,提取时间45 min,提取剂用量14.53 m L时,铅提取率最大.方法的加标回收率为84.0%~106%,相对标准偏差(RSD)在4.5%~6.1%之间,检出限为1.4μg·L^(-1).t检验结果表明超声提取法与加热板消解法及微波消解法(行业标准)之间不存在显著性差异,但超声提取法更为简便、快速、温和、安全.本方法应用于测定锦州市渤海大学(1~#)、解放路(2~#)、中央大街(3~#)、世博园(4~#)四个代表性采样点的PM_(2.5)中Pb的含量,其中2~#和3~#采样点的Pb污染最严重,分别为0.33μg·m^(-3)和0.41μg·m^(-3).虽然四个采样点Pb含量均未超过Pb浓度限值(0.5μg·m^(-3)),但Pb富集因子很高(>100),表明Pb在大气颗粒物中富集明显,受人类活动影响较大.
The optimized extraction conditions,such as solvent amount,ultrasonic time and ultrasonic temperature,of Pb in PM_(2.5) are obtained by a Plackett-Burman design and response surface methodology on the basis of single factor experiment.The results show that Pb has the maximum extraction rate under the optimal condition that ultrasonic temperature is 95 ℃,ultrasonic time is 45 min and solvent amount is 14.53 m L.The recovery is 84.0%~ 106%,relative standard deviation(RSD) is 4.5% ~ 6.1%,the limit of detection is 1.4 μg·L^(-1).The results of tese show that there is no significant difference between the ultrasound assisted extraction,hotplate digestion and microwave digestion method(industry standards).The ultrasonic extraction is more simpler,faster,milder and safer.This ultrasonic extraction was applied to the determination of Pb in PM_(2.5) at Bo Hai University(1~#),Jie Fang Road(2~#),Centre Street(3~#) and Expo Park(4~#).The sampling points of 2~# and 3~# are the most highly contaminated with Pb,the enrichment factor are 0.33 μg·m^(-3) and 0.41 μg·m^(-3) respectively.Though the concentrations of Pb do not exceed concentration limits(0.5 μg·m^(-3)),the high enrichment factors(> 100) show that Pb is enriched in the atmospheric particulates,and human action of a greater impact on the Pb.
出处
《渤海大学学报（自然科学版）》
CAS
2017年第3期239-245,共7页
Journal of Bohai University:Natural Science Edition
基金
国家自然科学基金项目(No:21676028)
关键词
超声提取法
响应面分析法
PM2.5
铅
ultrasound assisted extraction
response surface method
PM2.5
lead
