绿咖啡中赭曲霉毒素A的检测，第一部分：方差分量估计

Testing green coffee for ochratoxin A, part I: estimation of variance components.

作者信息

Vargas Eugenia A, Whitaker Thomas B, Santos Eliene A, Slate Andrew B, Lima Francisco B, França Regina C A

机构信息

Ministério da Agricultura, Pecuária e Abastecimento, Laboratório de Controle de Qualidade e Segurança Alimentar/LAV-MG, Av. Raja Gabaglia, Cidade Jardim, Belo Horizonte, Minas Gerais, Brazil.

出版信息

J AOAC Int. 2004 Jul-Aug;87(4):884-91.

PMID:15295883

Abstract

The variability associated with testing lots of green coffee beans for ochratoxin A (OTA) was investigated. Twenty-five lots of green coffee were tested for OTA contamination. The total variance associated with testing green coffee was estimated and partitioned into sampling, sample preparation, and analytical variances. All variances increased with an increase in OTA concentration. Using regression analysis, mathematical expressions were developed to model the relationship between OTA concentration and the total, sampling, sample preparation, and analytical variances. The expressions for these relationships were used to estimate the variance for any sample size, subsample size, and number of analyses for a specific OTA concentration. Testing a lot with 5 microg/kg OTA using a 1 kg sample, Romer RAS mill, 25 g subsamples, and liquid chromatography analysis, the total, sampling, sample preparation, and analytical variances were 10.75 (coefficient of variation [CV] = 65.6%), 7.80 (CV = 55.8%), 2.84 (CV = 33.7%), and 0.11 (CV = 6.6%), respectively. The total variance for sampling, sample preparation, and analytical were 73, 26, and 1%, respectively.

摘要

研究了检测大量生咖啡豆中赭曲霉毒素A（OTA）的变异性。对25批生咖啡豆进行了OTA污染检测。估计了与检测生咖啡豆相关的总方差，并将其划分为采样、样品制备和分析方差。所有方差均随OTA浓度的增加而增加。通过回归分析，建立了数学表达式来模拟OTA浓度与总方差、采样方差、样品制备方差和分析方差之间的关系。这些关系的表达式用于估计特定OTA浓度下任何样本量、子样本量和分析次数的方差。使用1 kg样本、Romer RAS磨、25 g子样本和液相色谱分析对含5 μg/kg OTA的一批样本进行检测，总方差、采样方差、样品制备方差和分析方差分别为10.75（变异系数[CV]=65.6%）、7.80（CV=55.8%）、2.84（CV=33.7%）和0.11（CV=6.6%）。采样、样品制备和分析的总方差分别为73%、26%和1%。