Jurdáková Helena, Górová Renáta, Addová Gabriela, Šalingová Anna, Ostrovský Ivan
Institute of Chemistry, Faculty of Natural Sciences, Comenius University, Mlynská dolina CH-2, Ilkovičova 6, 84215 Bratislava, Slovakia.
Institute of Chemistry, Faculty of Natural Sciences, Comenius University, Mlynská dolina CH-2, Ilkovičova 6, 84215 Bratislava, Slovakia.
Anal Biochem. 2018 May 15;549:113-118. doi: 10.1016/j.ab.2018.03.018. Epub 2018 Mar 19.
Flow injection analysis-tandem mass spectrometry has become widely used for analysis of many biomarkers in various biological matrices. To improve the sensitivity, the compounds are often determined as their butylesters. Since the concentration of urinary excreted compounds are generally reported after normalization to creatinine, the aim of this study was to investigate the possibility of creatinine determination in urine samples which underwent butylation. The impact of derivatization on urinary creatinine determination was investigated by measuring of underivatized and derivatized samples. The 10% creatine to creatinine conversion was observed during butylation, what above 700 μmol creatine/mmol creatinine caused significant creatinine overestimation. In that case, correction for creatine conversion rate was done. QC samples at six concentration levels were examined and precision and accuracy values fulfill the European Medicine Agency validation requirements. The elaborated method was applied for determination of creatinine in 41 real human urine samples. Determined creatinine concentrations were in the range of 0.27-22.3 mmol/L, linearity was confirmed within the concentration range of 0.27-31.7 mmol/L. Obtained results highly correlated with routinely used enzymatic assay for all tested samples and proposed method provide reliable determination of creatinine in butylated urine in a single run with butylesters of other analytes of interest.
流动注射分析-串联质谱已广泛用于分析各种生物基质中的多种生物标志物。为提高灵敏度，化合物常以其丁酯形式进行测定。由于尿中排泄化合物的浓度通常在以肌酐进行归一化后报告，本研究的目的是探讨对经过丁基化处理的尿液样本进行肌酐测定的可能性。通过测量未衍生化和衍生化的样本，研究了衍生化对尿肌酐测定的影响。在丁基化过程中观察到10%的肌酸向肌酐的转化，当肌酸/肌酐超过700μmol/mmol时会导致肌酐显著高估。在这种情况下，对肌酸转化率进行了校正。对六个浓度水平的质控样本进行了检测，精密度和准确度值符合欧洲药品管理局的验证要求。所阐述的方法应用于41份真实人类尿液样本中肌酐的测定。测定的肌酐浓度范围为0.27 - 22.3mmol/L，在0.27 - 31.7mmol/L的浓度范围内确认了线性关系。对于所有测试样本，获得的结果与常规使用的酶法高度相关，并且所提出的方法能够在单次运行中与其他感兴趣分析物的丁酯一起可靠地测定丁基化尿液中的肌酐。
