This study aims to establish joint fluid reference levels for Chromium (Cr) and Cobalt (Co) in a reference population of available fluid types. Method performance was evaluated on an existing urine matrix calibration method using inductively coupled plasma-mass spectrometry. Method performance characteristics, including intra- and inter-assay imprecision, accuracy, linearity, AMR (analytical measurement range), sensitivity, and carryover were determined in accordance with clinical laboratory standards. Additionally, analytical and clinical recoveries were assessed to investigate comparability between available joint fluid types and existing calibrators prepared in urine to demonstrate acceptability of a matrix-substitution design. 124 de-identified joint fluid samples submitted for unrelated testing were used to establish the reference levels. Reference levels were determined, by using the 97.5th percentile, to be <20.4 µg/L for Cr and <29.9 µg/L for Co. In addition, the presented method overcomes the lack of an ample volume of joint fluid to use for matrix matched calibrators by employing a urine-based calibration curve. The data demonstrate acceptable matrix comparability.

本研究旨在建立可用液体类型参考人群中铬 (Cr) 和钴 (Co) 的关节液参考水平。使用电感耦合等离子体质谱法根据现有的尿液基质校准方法评估方法性能。方法性能特征，包括测定内和测定间不精密度、准确性、线性、AMR（分析测量范围）、灵敏度和残留均根据临床实验室标准确定。此外，还评估了分析和临床回收率，以研究现有关节液类型与尿液中制备的现有校准品之间的可比性，以证明基质替代设计的可接受性。提交用于无关测试的 124 个未识别的关节液样本被用来建立参考水平。使用第 97.5 个百分位数确定 Cr 的参考水平为 <20.4 µg/L，Co 的参考水平为 <29.9 µg/L。此外，所提出的方法克服了缺乏足够体积的关节液的问题通过采用基于尿液的校准曲线来用于基质匹配校准品。数据证明了可接受的矩阵可比性。