气溶胶中苯并[k]荧蒽的恒能量同步荧光测量条件优化  

Optimization of parameters for the determination of aerosol benzo[k]fluoranthene by constant energy synchronous luminescence spectrometry

作　　者：蔡小琼[1] 王伯光[1] 刘慧璇[1] 

机构地区：[1]暨南大学环境工程系,广东广州510632

出　　处：《中国环境科学》2011年第8期1256-1262,共7页China Environmental Science

基　　金：广东省科技攻关项目(2007B030102004);国家科技部863项目子题(2006AA06A308)

摘　　要：采用正交实验研究光电倍增管（PMT）工作电压、激发单色器狭缝带宽（EX slit）和发射单色器狭缝带宽（EM slit）等对恒能量同步荧光测量技术的精密度、灵敏度、检出限及半峰宽度的影响机理,筛选和优化气溶胶中苯并[k]荧蒽的最佳测量条件.结果表明,3个因素对精密度、灵敏度、检出限均有显著影响,但只有EX slit带宽对半峰宽度有显著影响.PMT的工作电压越高,精密度越低,灵敏度越高,而它对检出限的影响较为复杂,当PMT工作电压为800V时,检出限可达到最低值;EX slit带宽越大,精密度越高,灵敏度越低,检出限越低,半峰宽度越大;EM slit带宽越大,精密度越低,灵敏度越高,检出限越低.模拟实验优化后的最佳测试条件为PMT工作电压800V、EX slit带宽2.5nm以及EM slit带宽5nm,.此时的最低检测限为0.086ng/mL,能适合于在线检测的技术要求.在环境实际气溶胶样品苯并[k]荧蒽含量的测量时,该方法与HPLC-FLD的测量值差异较小,两者的差值范围为1.73~10.70%,具有很好的可比性.In order to optimize measurement parameters when using constant energy synchronous luminescence spectrometry to determine benzo[k]fluoranthene in atmospheric aerosols,orthogonal experiments were conducted to study the impact of photomultiplier（PMT） voltage,excitation monochromator slit bandwidth（EX-slit） and emission monochromator slit bandwidth（EM-slit） on the precision,sensitivity,detection limit and half-height peak width.The results showed that all the three factors had significant influence on the precision,sensitivity and detection limit,but only EX-slit had significant impact on half-height peak width.Declining of precision and growing of sensitivity were observed when increasing PMT voltage.Detection limits,however,revealed a complex nonlinearity relationship with PMT voltage and reached their minimums with PMT voltage at 800V.With the enlargement of EX-slit,precisions were improved but half-height peak widths were also increased with lower detection limits and worse sensitivities.With the growing EM-slit,sensitivity was improved but detection limit and precision were declining.Based on the orthogonal tests the optimized measurement parameters included PMT voltage of 800V,EX-slit of 2.5nm and EM-slit of 5nm.The lowest detection limit under these optimized conditions was 0.086ng/mL,which is technically suitable for on-line monitoring of benzo[k]fluoranthene.For benzo[k]fluoranthene in environmental aerosol samples,results measured by constant energy synchronous luminescence spectrometry agreed quite well with those by high performance liquid chromatography equipped with fluorescence detector.The differences between them ranged from 1.73% to 10.70%.

关 键 词：恒能量同步荧光光谱法 苯并[k]荧蒽 气溶胶 正交实验 

分 类 号：X132[环境科学与工程—环境科学]