供应美国NIST- SRM 3030临床检验材料标准物质单甲基胂酸标准溶液
SRM 3030 – Monomethylarsonic Acid Standard Solution 美国NIST- SRM 3030
产品名称 Description: Monomethylarsonic Acid Standard Solution
产品批号 Lot: N/A
产品有效期 Expiration Date: 3/31/2028 临床检验材料标准物质
产品包装 Unit of Issue: 2 x 5 mL
销售状态 Status: Now Selling
COA日期 Certificate Date: 8/22/2018 单甲基胂酸标准溶液
运输条件 Perishable: No
是否危险品 Hazardous Material: No
运输方式 Material Hazard Class: Not Hazardous to Ship
This Standard Reference Material (SRM) is intended for use as a primary calibration standard for the quantitative determination of monomethylarsonic acid (MMA). A unit of SRM 3030 consists of two 5 mL sealed borosilicate glass amber ampoules of water solution prepared gravimetrically to contain a known mass fraction of MMA.
Certified Mass Fraction Value of MMA (as As): 17.64 mg/kg ± 0.15 mg/kg k = 2.12
A NIST certified value  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 . The MMA 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  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  was utilized.For convenience of unit conversion, the density measured at 23.001 °C and the expanded uncertainty at approximately 95 % confidence for SRM 3030 are provided as (0.997631 ± 0.000027) g/mL.
MMA的认证质量分数值（as）：17.64 mg/kg±0.15 mg/kg k=2.12
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对砷杂质的测量采用离子色谱-电感耦合等离子体质谱法（IC-ICP-MS）和液相色谱-电感耦联等离子体质谱仪（LC-ICP-MS）。在可能的情况下，使用与总砷测量相同的方法将这些测量相结合。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。为了便于单位转换，在23.001°C下测量的密度和SRM 3030在约95%置信度下的扩展不确定度被提供为（0.997631±0.000027）g/mL。