供应美国NIST- SRM 3034可追溯标准物质砷胆碱标准溶液

供应美国NIST- SRM 3034可追溯标准物质砷胆碱标准溶液

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This Standard Reference Material (SRM) is intended for use as a primary calibration standard for the quantitative determination of arsenocholine (AC). A unit of SRM 3034 consists of two 5 mL sealed borosilicate glass amber ampoules of water solution prepared gravimetrically to contain a known mass fraction of AC. 美国NIST- SRM 3034可追溯标准物质

Certified Mass Fraction Value of AC (as As): 19.77 mg/kg ± 0.27 mg/kg k = 2.16

A NIST certified value [1] is a value for which NIST has the highest confidence in its accuracy in that all known or suspected sources of bias have been investigated or taken into account [2]. The AC value is calculated by subtracting the mass fraction of arsenic impurities from the mass fraction of total arsenic as detailed below. The expanded uncertainty, U, is calculated as U = kuc, where uc represents, at the level of one standard deviation, the combined effects of the between-method and the within-method components of uncertainty. The coverage factor, k, corresponds to an approximately 95 % level of confidence. The certified value is metrologically traceable to the derived SI unit for mass fraction, expressed as milligrams per kilogram.

The NIST measurements of total arsenic were made using inductively coupled plasma optical emission spectrometry (ICP-OES) and instrumental neutron activation analysis (INAA). These measurements were combined as the weighted means of the individual sets of measurements, estimated using a Gaussian random effects model [3] and the DerSimonian-Laird procedure [4,5]. The associated measurement uncertainty was evaluated by the application of the parametric statistical bootstrap, consistent with the ISO/JCGM Guide and its Supplement 1 [6-8].

The NIST measurements of arsenic impurities were made using ion chromatography inductively coupled plasma mass spectrometry (IC-ICP-MS) and liquid chromatography inductively coupled plasma mass spectrometry (LC-ICP-MS). When possible, these measurements were combined using the same approach as used for the total arsenic measurements. When arsenic impurity measurement values were observed to be below detection limits, the nonparametric Kaplan-Meier method for computing summary statistics of censored data [9] was utilized.For convenience of unit conversion, the density measured at 23.2 °C and the expanded uncertainty at approximately 95 % confidence for SRM 3034 are provided as (0.9980 ± 0.0013) g/mL.

本标准参考物质（SRM）旨在用作砷胆碱（AC）定量测定的主要校准标准。SRM 3034的一个单元由两个5 mL密封的硼硅酸盐玻璃琥珀色安瓿水溶液组成，该安瓿用重量法制备，含有已知质量分数的AC。 砷胆碱标准溶液

AC的认证质量分数值（as）：19.77 mg/kg±0.27 mg/kg k=2.16

NIST认证值[1]是NIST对其准确性具有最高信心的值，因为所有已知或怀疑的偏差源都已被调查或考虑[2]。AC值是通过从总砷的质量分数中减去砷杂质的质量分数来计算的，如下所述。扩展不确定度U计算为U=kuc，其中uc表示在一个标准偏差的水平上，方法间和方法内不确定度分量的综合影响。覆盖因子k对应于大约95%的置信水平。认证值在计量学上可追溯到质量分数的衍生国际单位制，单位为毫克/千克。

NIST使用电感耦合等离子体发射光谱法（ICP-OES）和仪器中子活化分析法（INAA）对总砷进行了测量。这些测量值被组合为单独测量集的加权平均值，使用高斯随机效应模型[3]和DerSimonian-Laird程序[4，5]进行估计。根据ISO/JCGM指南及其补充文件1[6-8]，通过应用参数统计自举来评估相关的测量不确定度。

NIST使用离子色谱-电感耦合等离子体质谱（IC-ICP-MS）和液相色谱-电感耦联等离子体质谱（LC-ICP-MS）对砷杂质进行测量。在可能的情况下，使用与总砷测量相同的方法对这些测量进行组合。当砷杂质测量值被观察到低于检测限时，使用非参数Kaplan-Meier方法计算截尾数据的汇总统计[9]。为了便于单位转换，SRM 3034在23.2°C下测量的密度和在约95%置信度下的扩展不确定度被提供为（0.9980±0.0013）g/mL。

产品规格Unit of Issue: 2 x 5 mL

产品有效期Product Expiration Date: 31 March 2028

产品储存温度NIST Storage Temperature: Refrigerate (4 o C)Please see certificate for user storage information regarding this material.

Safety Information

Table(s) of Related Materials 104.06 105.01

Hazard Class: This material is not considered hazardous to ship.

Perishable Types: Non-Perishable

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