伏安极谱法测定兔毛皮中可萃取甲醛含量的研究

The Determination of Formaldehyde in Rabbit Fur with Voltammetric Polarography

优化了伏安极谱仪测定甲醛含量的参数,测定了方法的线性范围和精密度,优选了萃取兔毛皮中甲醛的溶液和萃取温度,并对测定结果的精密度和回收率进行了评估,将测定结果与国标法测定结果进行了对比。实验结果表明:伏安极谱仪的测定甲醛的最适条件为:动态滴汞方式,高纯氮气通气时间600 s,富集时间60 s;甲醛浓度在400μg/L^200 mg/L时有良好的线性关系;精密度实验的相对标准偏差(n=10)为1.38%;用0.05 mol/L的氢氧化锂溶液在35℃萃取兔毛皮样品20 min,兔毛皮样品中甲醛含量为46.2 mg/kg,样品的重复性实验结果相对标准偏差(n=8)为2.15%;加标回收率在95.4%~103%之间;测定结果与国标法测定结果相比,相对偏差为1.44%;说明采用伏安极谱法测定兔毛皮中的甲醛含量结果准确、检测限低、重现性好。

The determination of formaldehyde with voltammetric polarography was researched. The parameters of the voltammetric polarograph instrument were optimized, the linear range and repeatability were determined. The solution and temperature for the extraction of formaldehyde from rabbit fur were researched. Then the sample solution was determined under given conditions by voltammetric polarography and the results were evaluated with repeatability test, recovery test and compared with that determined by National Standard method. The results showed that rabbit fur sample was extracted with 0.05 mol/L lithium hydroxide solution and the extracted sample solution mixed with lithium hydroxide- EDTA supporting electrolyte solution should be purged with oxygen free nitrogen gas for 600 s before deposition of formaldehyde was carried out by dropping mercury electrode（DME） for 60 s. There was a good linear relationship when the concentration of the sample solution changes from 400 μg/L to 200 mg/L. Relative standard deviations for 10 replicate determinations of formaldehyde standard solution were 1.38%. Formaldehyde content in rabbit fur sample determined was46.2 mg/kg. Relative standard deviations for 8 replicate determinations for rabbit fur sample were 2.15%. Recovery percentage was in the range of 95.4%-103%. Compared with National Standard method, the relative error of voltammetric polarography is 1.44%. The proposed method turned out to be accurate, convenient and sensitive with a low limitation and a good reproducibility.