微波消解-微波等离子体炬原子发射光谱法测定汽油中痕量铜和铁

Determination of Trace Copper and Iron in Gasoline by Microwave Digestion-MPT-AES

采用微波消解方法处理汽油样品，用微波等离子体炬原子发射光谱法（MPT—AES）测定消解液中的铜和铁含量。考察了微波功率、载气流量、工作气流量、酸效应、共存离子等实验参数对测定铜和铁的影响，并进行了系统优化，测得铜和铁的检出限分别为2．1ng／mL和22．1ng／ml。线性范围分别为0．01～12μg/mL和0．1～100μg／mL。详细考察了微波消解酸种类及用量，消解温度、运行时间及微波功率等对微波消解的影响。结果表明，各元素测定结果的RSD均小于3．5％，铜的回收率为93％-107％，铁的回收率为92％-106％。与传统的碘-二甲苯-硝酸反萃取处理法相比，此法具有元素损失少，操作简单，无需使用有毒氧化剂，减少污染，改善工作环境等优点，是行之有效的汽油样品预处理方法。

A method for the determination of trace copper and iron in gasoline by microwave plasma torch- atomic emission spectrometry （MFT-AES） with microwave digestion for sample pretreatment was developed. Comprehensive experimental parameters for MPT- AES, including microwave power, carrier gas flow rate, support gas flow rate, acidity and coexistence ions, and for microwave digestion, including acid type, digestion temperature, digestion time and microwave power were optimized. The detection limit and linear dynamic range for copper were 2.1 ng/mL and 0.01 - 12 μg/mL, respectively ; and those for iron were 22. 1 ng/mL and 0. 1 - 100μg/mL, respectively. The recoveries of copper and iron were 93% - 107% and 92% - 106% , respectively, and their RSD were less than 3.5%. Compared with the traditional iodine -xylene -nitric acid stripping method, microwave digestion is an environmental friendly method in digesting the gasoline sample.