如何消除基质干扰问题

<center>  </center>

摘要

背景：对测定血清肌酐浓度的Jaffe法进行定标时，应用一种以血清为基础并添加可以偿Jaffe法标准品中干扰的基质作用的人造基质混合溶液进行两点定标，其结果与酶法测定具有良好的可比性。

方法： 分光光度计法

结果：在Jaffe法测定中，常存在血清或血浆干扰物，一般通过减去一个固定常量的肌酐值以消除干扰。但是，在儿童检测中，使用本法处理数据会出现过度补偿的现象。利用一对由参比方法（同位素稀释质谱法）测定确定的初级血清标准品或者与初级标准品相关的一对二级标准品进行定标，可以使Jaffe法的试验结果与酶法具有良好的一致性。本定标法存在的问题：由于其他非肌酐干扰性色原出现在标准品中而使定标曲线存在吸光度削减；另外，在两点定标中，如果一个标准品中含有生理盐水或水，常会使定标曲线不平滑且存在扭曲。我们准备了一种可以补偿Jaffe法测定时血清标准品中干扰色原的人造血清基质并进行了测定。结果表明，即使仅使用一种含有人造基质的标准品进行标定，也可以获得两点法标定的结果，并且该结果与使用一对初级标准品定标的结果一致。

结论： 仅应用一种含标准基质并含有肌酐的血清标准品对Jaffe法进行两点定标，定标后，该法测定血清肌酐的结果和酶法结果具有良好的可比性。酶法是与参考性方法相关的标准方法。

 

关键词： Jaffe法中用于定标的人造血清基质、Jaffe发中血清干扰原补偿物、Jaffe法血清肌酐

文摘链接：http://www.reference-global.com/doi/abs/10.1515/CCLM.2008.224

------------------------------------------------------------------------------------------------
原文:

Determination of serum creatinine by Jaffe method and how to calibrate to eliminate matrix interference problems

Abstract
Background: The calibration of Jaffe method for serum creatinine using one serum-based standard complemented with artificial matrix compensating standard's Jaffe-interfering substances allows two-point calibration with results well comparable with enzymatic methods.
Method: Spectrophotometry was used.
Results: Jaffe procedures compensating serum/plasma intereferents by subtracting a constant amount of creatinine poorly overcompensate creatinine in children. Two-point calibration with a pair of primary serum standards certified by the reference measurement procedure (isotope-dilution, mass spectrometry) or with a pair of secondary standards linked to primary materials could provide results well agreeable with enzymatic determination. Such a calibration comprises an absorbance offset corresponding to other-than-creatinine Jaffe-interfering chromogens present in standards in the calibration line, while a two-point calibration combining one standard with physiological saline/water always grossly distorts calibration line. We calculated/prepared artificial serum matrices capable of compensating Jaffe-interfering chromogens in serum standards. The combination of even one standard with its artificial matrix also enables two-point calibration with practically the same results as with a pair of primary standards.
Conclusions: A two-point calibration of Jaffe method for serum creatinine combining only one serum standard with creatinine solution matching standard's allow matrix-present interferents present results well comparable with enzymatic determination, providing the standard is attested/linked to the reference measurement procedure.
Clin Chem Lab Med 2008;46:1127–33.
cal Chemistry and Laboratory Medicin