氯磺酚偶氮硫代若丹宁固相萃取光度法测定水中的汞

Study on the Solid Phase Extraction Spectrophotometric Determination of Mercury in Water with 5-(2-Hydroxy-4-Sulfo-5-Chlorophenol-1-Azo)-Thiorhodanine

研究了氯磺酚偶氮硫代若丹宁 (HSCT)与汞的显色反应 ,在pH 3 6的HAc NaAc缓冲介质中 ,HSCT与汞反应生成 2∶1稳定络合物 ,该络合物可被C18固相萃取小柱定量萃取富集 ,富集倍数达 80倍 ,小柱上保留的络合物用DMF洗脱后用分光光度法测定 ,在洗脱液中络合物λmax=5 4 5nm ,ε =6 2 4× 10 4L·mol-1·cm-1。汞含量在 0～ 1 5 μg·mL-1内符合比尔定律 ,方法用于水样中 μg·L-1级汞含量的测定 ,相对标准偏差在 1 8%～ 2 2 %之间 ,标准回收率在 93%～ 10 6 %之间 。

Based on the color reaction of mercury with 5-(2-hydroxy-4-sulfo-5-chlorophenol-1-azo)-thiorhodanine (HSTC) and the solid phase extraction of the colored complex with C-18 cartridge, a new method for the determinations mug(.)L(-1) level of mercury was studied. In the presence of pH 3.6 HAc-NaAc buffer solution. HSTC reacted with mercury (II) to form a stable 2:1 complex. This complex was enriched by solid phase extraction with C18 cartridge and the retained complex from cartridge was eluted with DMF. An enrichment factor of 80 was achieved. In the measured solution, the molar absorptivity was 6.24 x 10(4) L(.)moL(-1.)cm(-1) at 545 nm. Beer's law was obeyed in the range of 0-1.5 mug(.)mL(-1). This method was applied to the determination of mercury in water. The relative standard devitions were 1.8%-2.2% and the recoveries were 93%-106%. The results are satisfactory.