微波消解-ICP-MS法测定煤炭中汞、铍、砷和铀

Determination of Mercury,Beryllium,Arsenic,and Uranium in Coal Samples by Inductively Coupled Plasma-mass Spectrometry with Microwave Digestion

采用微波消解技术处理煤炭样品,建立了电感耦合等离子体质谱仪(ICPMS)测定煤炭中汞、铍、砷和铀元素的分析方法。分别选用不同配比及种类的酸进行微波消解处理,并采用内、外标法测定了煤炭中4种元素的含量。结果得出:采用5 m L浓硝酸和2 m L氢氟酸的混合酸微波消解0.2 g煤炭样品,可彻底将4种待测元素提取到待测溶液中,所得溶液透明澄清。在内标法中,选择了煤炭中含量较少的169Tm作为内标元素,4种元素的线性相关系数均大于0.999 9,所测两组数据的平行性接近,RSD<3%。进一步选择标准加入法准确测定了汞、砷、铍和铀元素的含量,所得4种元素的线性相关系数>0.999,汞、铍、砷和铀在煤炭中的含量分别为0.43、2.03、8.46和2.25 mg/kg。

Microwave digestion technology was used to treat coal samples,and a method for simultaneous determination of trace elements,such as mercury,beryllium,arsenic,and uranium in coal sample by inductively coupled plasma-mass spectrometry（ ICP-MS） was established. Different acids and their mixture with different ratio were used to treat coal sample by microwave digestion,and the internal standard method and standard addition method were used to measure the content of four elements in coal. The results showed that the mixture acid of 5 m L nitric acid and 2 m L hydrogen peroxide was the best choice it can digest the coal sample completely and make all the measured elements dissolve into the transparent solution.^169 Tm was used as the internal standard element in the internal standard method because of the low content in the coal sample. The correlation coefficients of four elements were greater than 0. 999 9,the results of two parallel tests were closed and the relative standard deviation（ RSD） value was lower than 3%. However,the results of recovery test for this internal standard method were unsatisfactory. Based on the internal standard method,standard addition method was used to measure the content of beryllium, arsenic, mercury and uranium. The correlation coefficients of four elements were greater than 0. 999,and the contents of Hg,Bi,As and U were 0. 43、2. 03、8. 46 and2. 25 mg / kg,respectively.