Rimayi Cornelius, Park Ju-Hyeong
Respiratory Health Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV 26505, USA.
Buildings (Basel). 2023;13(5). doi: 10.3390/buildings13051112.
Exposure to microbial agents in water-damaged buildings is a major public health concern. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) has become a primary tool for testing environmental samples for microbial secondary metabolites (SMs); however, matrix effects can lead to inaccurate results in exposure assessment. Applying a universal internal standard (ISTD) and a matrix-matched calibration can adjust for matrix effects, as shown by our previous study. However, there are only few isotope-labeled internal standards for SMs available on the market. In this study, we determined the best-performing ISTDs among ten candidates (nine C-labeled isotopes and one unlabeled analogue) for each of 36 SMs. We analyzed school floor dust spiked with the 36 SMs to identify the best-performing ISTDs (initial experiment) and examined reproducibility with the selected ISTDs and the same spiked dust (validation 1). We also tested applicability for the selected ISTDs using spiked dust collected from different schools (validation 2). The three experiments showed that 26, 17, and 19 SMs had recoveries within the range 100 ± 40%. C-ochratoxin A and C-citrinin were most frequently selected as the best ISTDs for the 36 SMs, followed by deepoxy-deoxynivalenol, C-sterigmatocystin, and C-deoxynivalenol. Our study shows that using the identified, best-performing analogous ISTDs for those metabolites may improve testing accuracy for indoor dust and help better estimate exposure effects on potential health.
接触受水损害建筑物中的微生物制剂是一个重大的公共卫生问题。液相色谱-串联质谱法（LC-MS/MS）已成为检测环境样品中微生物次级代谢产物（SMs）的主要工具；然而，基质效应可能导致暴露评估结果不准确。正如我们之前的研究所表明的，应用通用内标（ISTD）和基质匹配校准可以校正基质效应。然而，市场上可用于SMs的同位素标记内标很少。在本研究中，我们为36种SMs中的每一种确定了十种候选物（九种C标记同位素和一种未标记类似物）中表现最佳的ISTD。我们分析了添加了36种SMs的学校地板灰尘，以确定表现最佳的ISTD（初始实验），并使用选定的ISTD和相同的加标灰尘检验重现性（验证1）。我们还使用从不同学校收集的加标灰尘测试了选定ISTD的适用性（验证2）。这三个实验表明，26种、17种和19种SMs的回收率在100±40%范围内。C-赭曲霉毒素A和C-桔霉素最常被选为36种SMs的最佳ISTD，其次是去环氧脱氧雪腐镰刀菌烯醇、C-杂色曲霉素和C-脱氧雪腐镰刀菌烯醇。我们的研究表明，对这些代谢物使用已确定的、表现最佳的类似ISTD可能会提高室内灰尘的检测准确性，并有助于更好地估计对潜在健康的暴露影响。
