酸化吹气-气相分子法测定固体废物中硫化物

Determination of Sulfide in Solid Waste by Acidification Blowing-Gaseous Molecules Method

采用酸化吹气装置结合气相分子吸收光谱仪对固体废物中硫化物进行测定。考察酸性试剂的选取、加入量及酸化吹气反应时间对测定结果的影响,得出最佳的前处理条件为加入10 mL体积比为1∶1的磷酸,酸化吹气45 min。为确保吸收液中硫化物不被氧化,向吸收液中加入一定量抗氧化剂。结果表明:当抗氧化剂加入量为5 mL时,吸收液中硫化物的浓度可在6 h内保持稳定。方法的标准曲线相关系数为0.9999,检出限为0.19 mg/kg,实际固体废物样品的相对标准偏差为2.7%~6.1%,加标回收率为91.0%~93.0%。将气相分子吸收光谱法和亚甲基蓝分光光度法进行比对,结果表明2种方法对固体废物中硫化物的测定无显著差异。

Combined acidification blowing device and gas molecules absorption spectrometer method was applied to detect sulfide in solid waste.The impacts of acidic reagent’s choice,dosage and acidification blowing reaction time on determination results were discussed.The result showed that the optimum condition for pretreatment was adding 10 mL of phosphoric acid and 45 min of acidification blowing reaction time.To ensure the sulfide not to be oxidized,antioxidant was added in the absorption liquid,and the result showed that the sulfide concentration in absorption liquid could be stable within 6 h while the antioxidant’s dosage was 5 mL.The standard curve correlation coefficient of the method was 0.9999 and the detection limit was 0.19 mg/kg.The relative standard deviation of actual solid waste sample was in the range of 2.7%-6.1%,and the recovery rate was in the range of 91.0%-93.0%.Comparison of gas phase molecular absorption spectrometry and methylene blue spectrophotometric method was presented,and there was no significant difference in solid waste sulfide determination between the two methods.