摘要
目的建立称量法配制金属元素标准曲线的方法。方法利用万分之一分析天平和移液器,通过"衡量法",质量与实际体积计算测定标准溶液的密度。移取1 ml标准溶液于洁净塑料瓶中,记录其准确质量换算实际体积,按比例加入超纯水,使金属元素标准溶液介质的酸浓度稀释至1%,再加入1%的硝酸溶液至100 g,记录准确质量,按1%硝酸的密度计算稀释后体积,换算稀释后标液浓度,按照实际需求,配制相应的标准曲线浓度。标准系列的配制使用洁净塑料瓶,按质量比值稀释,计算实际浓度,完成配制过程。结果标准曲线相关系数r=1.000 0,环境水样质控检测结果准确,方法比对结果一致,称量法的不确定度与容量法的不确定度保持一致。结论本方法准确可靠、简便快捷、能够有效避免污染,适用于金属元素标准曲线的配制。
Objective To establish a method for preparing the standard curve of metal element by weighing method. Methods The density of the standard solution was calculated by using a 1/10 000 analytical balance and a pipette to determine the mass and actual volume. 1 ml standard solution was piped into a clean plastic bottle and the exact volume was noted for converting the actual volume. The ultrapure water was added proportionally to dilute the acid concentration of the metal standard solution into1%. Then 1% nitric acid solution was added up to 100 g and the accurate quality was recorded,finally the diluted volume was calculated according to the density of 1% nitric acid. The corresponding standard curve is prepared according to the actual demanding after contrasting the diluted standard concentration. Results The correlation coefficient was 1. 000 0,the results of environmental water quality controlling sample were accurate. The results of two methods were consistent. The uncertainty of the weighing method is consistent with the uncertainty of the volumetric method. Conclusion This method is accurate,simple and convenient,which can avoid pollution and is suitable for the preparing standard curve of metal elements.
引文
[1]中华人民共和国国家质量监督检验检疫总局.GB/T 27404—2008实验室质量控制规范食品理化检测[S],北京:中国标准出版社,2008.
[2]夏玉宇.化验员实用手册[M].北京:化学工业出版社,2015:9-11.
[3]刘丽,徐志勇,王俊超.称量法配制校准曲线的应用研究[J].化学工程师,2012(7):30-32.
[4]张英英,蒋斌.称量换算体积代替刻度移液管示值体积在标准曲线制作中的应用[J].浙江预防医学,2007,19(5):封3-封4.
[5]中华人民共和国国家质量监督检验检疫总局.JJG 646—2006移液器检定规程[S].北京:中国计量出版社,2007.
[6]赵海峰,张辉珍,谢寒冰,等.移液枪和移液管对测量结果不确定度的影响[J].中国卫生检验杂志,2015,25(21):3775-3778.
[7]中华人民共和国国家质量监督检验检疫总局.JJG 196—2006常用玻璃量器检定规程[S].北京:中国计量出版社,2007.
[8]Haynes WM,Lide David R,Bruno Thomas J.RCR Handbook of Chemistry and Physics[M].London:CRC Press,2015:5-135.
[9]侯建荣,潘心红,彭荣飞,等.ICP-MS法测定矿泉水中15种元素含量的不确定度分析[J].中国卫生检验杂志,2010,20(7):1802-1804.
[10]顾妍丽,宋振威,凌霞,等.ICP-MS法测定矿泉水中15种元素含量的不确定度分析[J].中国卫生检验杂志,2010,20(9):2360-2362.
[11]张国平,王云,蒋忠瑭.石墨炉原子吸收光谱法测定全血中铅含量的不确定度评定[J].中国卫生检验杂志,2010,20(10):2619-2620.
[12]吕卓欧.硝酸银容量法测定水中氯化物含量的不确定度评定[J].中国卫生检验杂志,2011,21(7):1817-1819.
[13]中华人民共和国国家质量监督检验检疫总局.JJF 1059.1—2012测量不确定度评定与表示[S].北京:中国质检出版社,2013.
[14]中华人民共和国国家质量监督检验检疫总局.JJG 1036—2008电子天平检定规程[S].北京:中国质检出版社,2008.
[15]罗建波,陈文胜.理化检验实验室质量管理工作指南[M].北京:中国质检出版社,2015:60-64.