氧化还原电位标准溶液电位值不确定度的评定  

Evaluation on Uncertainty of Measurement for Standard Solutions of Oxidation-Reduction Potential

作　　者：王媛[1] 刘大喜[1] 鞠美庭[1] 张川[2] 王颖臻[3] 李铁龙[1] 

机构地区：[1]南开大学环境科学与工程学院,天津300071 [2]国家海洋标准计量中心,天津300112 [3]昆明学院化学科学与技术系,云南昆明650504

出　　处：《南开大学学报（自然科学版）》2013年第2期17-21,共5页Acta Scientiarum Naturalium Universitatis Nankaiensis

基　　金：国家海洋公益性行业科研专项(200905028;201005026)

摘　　要：对硫酸亚铁铵-硫酸高铁铵溶液和氢醌溶液分别进行了从溶液配制、仪器测量和结果重复性3方面不确定度来源分析,确立了数学模型,综合评定了2者的合成标准不确定度和扩展不确定度.结果表明,氢醌溶液中,邻苯二甲酸氢钾缓冲溶液和磷酸盐缓冲溶液的合成标准不确定度分别为4.20mV和2.76mV,扩展不确定度分别为8.40mV和5.52mV(近似95%置信概率),都小于硫酸亚铁铵-硫酸高铁铵溶液的合成标准不确定度6.49mV和扩展不确定度12.98mV(近似95%置信概率).说明氢醌溶液电位值的测量结果更可信,精确度更高,应广泛作为测定氧化还原电位仪器的标准溶液来使用.Two Oxidation-Reduction Potential standard solutions are the foundation and the key that a potentiometer can measure ORP accurately and steadily. Therefore, sources of uncertainty were analyzed in preparation of standard solutions,measurement using precision po- tentiometer and repeatability for ammonium ferrous sulphate-ferric ammonium sulfate solution and hydroquinone solution （included potassium hydrogen phthalate buffer solution and phos- phate buffer solution）, respectively. Mathematical model was established, and the two com- bined standard uncertainty and expanded uncertainty were assessed synthetically. The results showed that combined standard uncertainty and expanded uncertainty of potassium hydrogen phthalate buffer solution and phosphate buffer solution are 4.20 and 2.76 mV, 8.40 and 5.52 mV（approximate 95 % confidence level）, which both are less than the values of ammonium fer- rous sulphate-ferric ammonium sulfate solution. The measurement results of hydroquinone so- lution potential values are more credible, more accurate, and more widely used as standard so- lution for potentiometers.

关 键 词：硫酸亚铁铵-硫酸高铁铵溶液 氢醌溶液 氧化还原电位标准溶液 不确定度评定 

分 类 号：P7[天文地球—海洋科学] TB9[一般工业技术—计量学]