不同饮水砷测定方法的比对

Comparison between different methods for determination of arsenic in drinking water

目的 比对砷斑法 (速测法 )、二乙氨基二硫代甲酸银分光光度法 (DDCAg法 )、石墨炉原子吸收法 (GF-AAS法 ) 3种饮水砷含量测定方法的可靠性。方法 分别采用速测法、DDCAg法、GF- AAS法对 318份含砷饮水样进行比对分析。对 34份用速测法和 DDCAg法测定结果不一致的以及水砷 >0 .5 mg/ L 的样品再用 GF- AAS法测定。测定结果分别进行 χ2检验和 t检验。结果 速测法与 DDCAg法测定结果符合率为 91% ,速测法与用GF- AAS法修正过的 DDCAg法测定结果符合率为 97%。水砷 <0 .5 m g/ L 的水样用 DDCAg法和 GF- AAS法所测结果差异无显著意义 ,水砷 >0 .5 mg/ L 的水样则差异有极显著意义。结论 DDCAg法是目前国内测定饮水砷的首选方法 ,GF- AAS法有代替 DDCAg法的趋势。但是在砷中毒调查中 ,速测法是较实用、可靠的饮水砷测定方法。

Objective To verify the reliability of three methods with comparison between the Arsenical spot method (rapid method), Silver diethyl dithiocarbamate method (DDCAg method) and atomic absorption sepectrophotometry(GF AAS method) for determination of arsenic(As).Methods 318 drinking water samples were comparatively determined by rapid method, DDCAg method and GF AAS method. 34 samples of them which the data of DDCAg method were not conformable to that of rapid method and their As contents over 0.5 mg/L were selected to be determined by GF AAS method. The statistical analysis for the determination with different methods was depended on the chi square test and significance test.Results The conformability rate of the results which were compared between the rapid method and DDCAg method was 91%. And that of which the rapid method's results were compared with the DDCAg method's results revised by GF AAS method was 97%. There was no significance of the difference for the As contents below 0.5 mg/L between DDCAg method and GF AAS method and there was extremely significance of the difference for those over 0.5 mg/L.Conclusions DDCAg method is the first chosen method on the determination for the arsenic of drinking water. There is a tendency of that will be replaced by GF AAS method. The rapid method is really practical, reliable method on the arsenism survey.