高灵敏度串联薄层溶出电解池研制及在尿铅测定中的应用

将薄层大面积玻碳电解池与小面积玻碳电解池以串联方式连接,在程控状态下使用.铅离子首先在大面积玻碳汞膜电极(LGCE)上预富集,溶出后在小面积玻碳汞膜电极(SGCE)上两次富集,因此提升了SGCE富集效率.测量25 0μg/L铅标准溶液,峰高的相对标准偏差RSD=1.2％.测量铅含量为25.6 μg/L的尿样,测得值27.4μg/L,相对标准偏差RSD=2 3％.富集时间400 s检出限为0.008 8 μg/L;定量检测限为0.029 2 μg/L.与常规的溶出分析比较,检出限降低11 90倍,显著提高检测的灵敏度.流动式电解池在溶出时的底液中不含样品基体.

Preparation of thin-layer stripping electrolytic cell in series with high sensitivity and application in determination of urinary lead

The thin-layer large area of the glassy carbon electrolytic cell and the small area of the glassy carbon electrolytic cell are connected in series and used under the program control.Lead ions firstly make pre-enrichment on the large area of glassy carbon mercury film electrode(LGCE),and then they make the second enrichment on the small area of glassy carbon mercury film electrode(SGCE) after stripping,thus it raise the enrichment efficiency of the SGCE.It measures 25.0 μg/L lead standard solution and gets the relative standard deviation of peak height RSD=1.2%.It measures urine sample with lead content of 25.6 μg/L and the measured value it gets is 27.4 μg/L,and the relative standard deviation RSD=2.3%.In the enrichment time of 400 s,its detection limit is 0.008 8 μg/L and quantitative detection limit is 0.029 2 μg/L.Compared with conventional stripping analysis,the detection limit reduces 11.90 times to significantly improve the detection sensitivity.The base solution of flowing electrolytic cell does not contain the sample matrix when stripping.