58117 Dr. Risch Ostschweiz AG , Buchs, Switzerland.
111618 Roche Diagnostics GmbH , Penzberg, Germany.
Clin Chem Lab Med. 2024 Mar 22;62(7):1339-1351. doi: 10.1515/cclm-2023-1045. Print 2024 Jun 25.
A reference measurement procedure (RMP) using isotope dilution liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS) was developed and validated with the aim of accurately measuring carbamazepine-10,11-epoxide concentrations in human serum and plasma.
To establish traceability to SI units, the absolute content of the reference material was determined using quantitative nuclear magnetic resonance (qNMR) spectroscopy. As sample preparation a protein precipitation protocol followed by a high dilution step was established. Chromatographic separation from carbamazepine and potential metabolites was achieved using a C18 stationary phase. Selectivity, specificity, matrix effects, precision and accuracy, inter-laboratory equivalence, and uncertainty of measurement were evaluated based on guidelines from the Clinical and Laboratory Standards Institute, the International Conference on Harmonization, and the Guide to the Expression of Uncertainty in Measurement.
The RMP demonstrated very good selectivity and specificity, showing no evidence of a matrix effect. This enabled accurate quantification of carbamazepine-epoxide in the concentration range of 0.0400-12.0 μg/mL. The intermediate precision was found to be less than 2.1 %, and the repeatability coefficient of variation (CV) ranged from 1.2 to 1.8 % across all concentration levels. Regarding accuracy, the relative mean bias varied from 1.4 to 2.5 % for native serum levels and from 1.4 to 3.5 % for Li-heparin plasma levels. The measurement uncertainty for single measurements ranged from 1.6 to 2.1 %.
In this study, we introduce a new LC-MS/MS-based candidate RMP for accurately measuring carbamazepine-10,11-epoxide in human serum and plasma. This novel method offers a traceable and dependable platform, making it suitable for standardizing routine assays and assessing clinically relevant samples.
建立了一种使用同位素稀释液相色谱-串联质谱法（ID-LC-MS/MS）的参考测量程序（RMP），旨在准确测量人血清和血浆中的卡马西平 10,11-环氧化物浓度。
为了实现与 SI 单位的溯源性，使用定量核磁共振（qNMR）光谱法确定参考物质的绝对含量。作为样品制备，建立了一种蛋白质沉淀方案，随后进行高稀释步骤。使用 C18 固定相实现与卡马西平和潜在代谢物的色谱分离。根据临床和实验室标准协会、国际协调会议和测量不确定度指南，评估了选择性、特异性、基质效应、精密度和准确度、实验室间等效性和测量不确定度。
该 RMP 表现出非常好的选择性和特异性，没有证据表明存在基质效应。这使得能够在 0.0400-12.0μg/mL 的浓度范围内准确定量卡马西平-环氧化物。中间精密度小于 2.1%，重复性变异系数（CV）在所有浓度水平下为 1.2-1.8%。关于准确性，天然血清水平的相对平均偏差为 1.4-2.5%，Li-肝素血浆水平的相对平均偏差为 1.4-3.5%。单次测量的测量不确定度范围为 1.6-2.1%。
在这项研究中，我们引入了一种新的基于 LC-MS/MS 的候选 RMP，用于准确测量人血清和血浆中的卡马西平 10,11-环氧化物。这种新方法提供了一个可溯源且可靠的平台，使其适合标准化常规测定和评估临床相关样本。
