Analytical performance of stable isotope-labeled internal standardization (SIL-IS) and threshold accurate calibration (TAC) methods of matrix normalization are compared for quantitation of 51 drugs and metabolites (analytes) in urine with analysis by ultra performance liquid chromatography with tandem mass spectrometry (UPLC–MS-MS). Two SIL-IS methods of analysis were performed, one method using analyte-specific internal standardization (ASIL-IS) and another method using a shared stable isotope from another analyte for internal standardization (SSIL-IS). Variance in inter-specimen matrix effect, without the use of a matrix normalization method, was studied by UPLC–MS-MS analysis of 338 urine donor samples and showed >200% variation in ion response for some analytes. Matrix normalization methods were evaluated for precision, accuracy, calibration, multi-matrix recovery and positive casework quantitation. Acceptable calibration and quality control criteria were achieved for all methods when calibrators and controls were prepared from the same urine matrix pool. Quantitative accuracy, determined by the addition of analytes to multi-donor urine pools at two concentration levels, resulted in acceptable percent relative standard deviation (%RSD) and bias for TAC and ASIL-IS methods. SSIL-IS method quantitations in analyte-supplemented donor pools revealed a %RSD ranging from 20% to 60% for >30% of the analytes and a method bias that ranged up to 87%, with a differential matrix effect on analyte and shared internal standard accounting for the imprecision and bias. Analyte quantitation in 162 authentic case samples showed close agreement for TAC and ASIL-IS methods, with greater variance in the SSIL-IS method. The study demonstrates effective matrix normalization by ASIL-IS and TAC methods and a matrix-caused bias in the SSIL-IS method.

中文翻译：

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用于确定性尿液药物检测的矩阵标准化技术

通过超高效液相色谱和串联质谱法对尿液中 51 种药物和代谢物（分析物）的定量分析比较了稳定同位素标记内标 (SIL-IS) 和基质标准化阈值精确校准 (TAC) 方法的分析性能(UPLC-MS-MS)。执行了两种 SIL-IS 分析方法，一种方法使用特定于分析物的内部标准化 (ASIL-IS)，另一种方法使用来自另一种分析物的共享稳定同位素进行内部标准化 (SSIL-IS)。通过 UPLC-MS-MS 分析对 338 个供尿者样品进行了不使用基质归一化方法的样本间基质效应的变异研究，结果显示某些分析物的离子响应变异大于 200%。评估矩阵归一化方法的精度、准确度、校准、多基质回收和阳性个案定量。当校准品和对照品从相同的尿液基质池中制备时，所有方法都达到了可接受的校准和质量控制标准。通过向多供体尿液池中添加两个浓度水平的分析物确定的定量准确性导致 TAC 和 ASIL-IS 方法的相对标准偏差百分比 (%RSD) 和偏差可接受。SSIL-IS 方法定量分析补充了分析物的供体池，结果显示，大于 30% 的分析物的 %RSD 范围为 20% 至 60%，方法偏差高达 87%，对分析物和共享的基质有不同的影响内部标准考虑了不精确性和偏差。162 个真实案例样品中的分析物定量显示与 TAC 和 ASIL-IS 方法非常一致，SSIL-IS 方法的差异更大。该研究证明了 ASIL-IS 和 TAC 方法的有效矩阵归一化以及 SSIL-IS 方法中的矩阵导致的偏差。