Clancy Vincent, Willie Scott
Institute for National Measurement Standards, National Research Council of Canada, Ottawa, Ontario, Canada.
Anal Bioanal Chem. 2004 Mar;378(5):1239-42. doi: 10.1007/s00216-003-2473-1. Epub 2004 Jan 24.
There is an urgent need for natural water reference materials certified for nutrients. In 1996, NRC collected seawater for a proposed CRM at a depth of 200 m in the North Atlantic; this was immediately filtered through 0.05-microm cartridge filters into 50-L carboys. The water was later homogenized in the NRC laboratories in Ottawa and stabilized via gamma irradiation. Over six years of stability testing no significant deterioration was detected. In addition to the usual customary standard colorimetric procedures, alternative analytical methods were developed to enable the certification process. The production of a CRM called MOOS-1 will be discussed. Certified values, with uncertainty components addressing the homogeneity, stability, and characterization of the material, were calculated to be: orthophosphate=1.56+/-0.07 micro mol L(-1), silicate=26.0+/-1.0 micro mol L(-1), nitrite=3.06+/-0.15 micro mol L(-1), and nitrite and nitrate=23.7+/-0.9 micro mol L(-1).
迫切需要经过认证的天然水营养物质参考材料。1996年，加拿大国家研究委员会（NRC）在北大西洋200米深处采集海水用于拟议中的有证标准物质（CRM）；海水立即通过0.05微米的筒式过滤器过滤到50升的大玻璃瓶中。这些水后来在渥太华的NRC实验室中进行了均质化处理，并通过伽马辐照进行了稳定化处理。经过六年的稳定性测试，未检测到明显的变质。除了常规的标准比色法外，还开发了替代分析方法以推动认证过程。将讨论一种名为MOOS - 1的有证标准物质的生产情况。经计算得出的认证值及其不确定度分量涵盖了该物质的均匀性、稳定性和特性表征，具体为：正磷酸盐 = 1.56 ± 0.07微摩尔/升，硅酸盐 = 26.0 ± 1.0微摩尔/升，亚硝酸盐 = 3.06 ± 0.15微摩尔/升，亚硝酸盐和硝酸盐 = 23.7 ± 0.9微摩尔/升。
