在4种不同酸体系下测定电焊烟尘滤膜平行样品中锰含量的乙炔-空气火焰原子吸收光谱测定法

Determination of manganese content in welding fume filter parallel samples by acetylene-air flame atomic absorption spectrometry:digestion with four different acid systems

目的结合乙炔-空气火焰原子吸收光谱法,比较电焊烟尘滤膜平行样品在硫酸、硝酸、高氯酸与混合酸(V_(硝酸)∶V_(高氯酸)=9∶1)等4种不同酸体系下消解后测定锰含量的变化。方法在某煤矿机修厂铆焊车间电焊工作业点下风侧采集电焊烟尘滤膜平行样品4个(1~#~4~#滤膜),采用硫酸、硝酸、高氯酸与混合酸等4种不同的酸体系分别在电热板上对其进行消解,消解后用0.12 mol/L盐酸溶液定容,采用乙炔-空气火焰原子吸收光谱法测定其锰含量,同时做空白对照,比较含锰电焊烟尘滤膜样品在不同酸体系下消解后测定结果的变化。结果锰的标准曲线:Y=0.153 5X+0.003 4,相关系数0.999 7,检出限为0.017μg/ml,标准曲线在0.20~3.00μg/ml之间线性良好,质控样浓度范围:1.41±0.06 mg/L,实测均值:1.39 mg/L,符合要求。使用硫酸消解,测得溶液中锰浓度0.691~0.723μg/ml,RSD为1.7%;使用硝酸消解,测得溶液中锰浓度为1.137~1.179μg/ml,RSD为1.2%;使用高氯酸消解,测得溶液中锰浓度1.134~1.176μg/ml,RSD为1.4%;使用混合酸消解,测得溶液中锰浓度1.138~1.198μg/ml,RSD为2.0%。结论使用4种不同酸体系消解电焊烟尘滤膜平行样品,测得锰含量均值由大到小分别为混合酸、硝酸、高氯酸、硫酸。其中硝酸、高氯酸与国标中混合酸消解后测得锰含量接近,硫酸消解后测得锰含量与国标中混合酸差别较大。

[Objective]On the basis of acetylene-air flame atomic absorption spectrometry,to compare the differences in manganese content of welding fume filter parallel samples which were digested with 4 different acid systems,including sulfuric acid,nitric acid,perchloric acid and mixed acid（V_（nitric acid）∶ V_（perchloric acid）=9 ∶ 1）.[Methods]4 welding fume filter parallel sam-ples（1^#-4^# filter membrane） were collected at downwind side of welding operation point of welding workshop in a coal mine ma-chinery repair plant. The parallel samples were separately digested with sulfuric acid,nitric acid,perchloric acid and mixed acid on the electric heating plate,and 0.12 mol/L hydrochloric acid solution was used for constant volume. The manganese content was determined by acetylene-air flame atomic absorption spectrometry,and a blank control group was set up at the same time. The determination results of welding fume filter samples which were digested with different acid systems were compared.[Results]The standard curve of manganese was Y =0.153 5X ＋0.003 4,the correlation coefficient was 0.999 7 and the detection limit was0.017 μg/ml,the standard curve showed good linearity in the range of 0.20-3.00 μg/ml,the quality control sample concentration range was 1.41±0.06 mg/L,and the measured value was 1.39 mg/L,which met the requirements. Using sulfuric acid digestion,the manganese concentration was 0.691-0.723 μg/ml with RSD of 1.7%. Using nitric acid digestion,the manganese concentration was1.137-1.179 μg/ml with RSD of 1.2%. Using perchloric acid digestion,the manganese concentration was 1.134-1.176 μg/ml with RSD of 1.4%. Using mixed acid digestion,the manganese concentration was 1.138-1.198 μg/ml with RSD of 2.0%.[Conclusion]After the welding fume filter parallel samples are digested with 4 different acid systems,the measured manganese content from large to small is respectively mixed acid,perchloric acid,nitric acid,perchlorate acid,sulfuric acid. The measured values of nitric acid and perchlorate acid digestion are closest to the manganese content of mixed acid digestion in national standard method,while the measured value of sulfuric acid digestion is differ greatly from the result of national standard method.