Triclosan (TCS) is commonly used in home and personal care products (HPCPs), which causes it to be ubiquitously detected in aquatic environments. The toxicity of triclosan to aquatic organisms can vary at different pH values because the ionization states of TCS affect its bioaccumulation properties. The objective of this study was to examine the pH-dependent toxicity of TCS on embryonic zebrafish (Danio rerio) using a metabolomic profiling method based on gas chromatography-mass spectrometry (GC–MS). Exposure experiments were conducted on zebrafish embryos at three pH conditions (6, 7, and 8) and two TCS concentrations (30 μg/L and 300 μg/L). Metabolic profiles were obtained by extracting intracellular metabolites. Univariate (One-way ANOVA) and multivariate (PLS-DA) analyses were conducted to determine the metabolomic changes in TCS-treated embryos. Changes in the metabolic profile revealed that interference in biological pathways were induced by mostly ionized TCS (low pH) and high TCS concentrations. Also, fold changes in metabolite profiles showed that the TCS toxicity was a function of pH. Metabolites including urea, D-glucose, D-galactose, phenylalanine, L-glutamic acid, citric acid, and phosphoric acid showed significant changes under different pH conditions (p-value < 0.05). Our metabolomics study revealed that the responses of metabolites to TCS toxicity were pH-dependent. The differences of the responses could be attributed to the bioaccumulation capability of TCS, which increased as the ionized TCS proportion increased under low pH conditions.

三氯生（TCS）通常用于家庭和个人护理产品（HPCP）中，这导致在水生环境中普遍检测到三氯生。三氯生对水生生物的毒性在不同的pH值下可能会发生变化，因为TCS的电离状态会影响其生物蓄积性能。这项研究的目的是检查TCS对胚胎斑马鱼（Danio rerio）使用基于气相色谱-质谱（GC-MS）的代谢组学分析方法。在三个pH条件（6、7和8）和两个TCS浓度（30μg/ L和300μg/ L）下对斑马鱼胚胎进行了暴露实验。通过提取细胞内代谢物获得代谢概况。进行单因素（单向方差分析）和多元（PLS-DA）分析，以确定经TCS处理的胚胎的代谢组学变化。代谢谱的变化表明，大部分离子化的TCS（低pH）和高TCS浓度可诱导对生物途径的干扰。同样，代谢物谱的倍数变化表明TCS毒性是pH的函数。代谢物包括尿素，D-葡萄糖，D-半乳糖，苯丙氨酸，L-谷氨酸，柠檬酸，磷酸在不同的pH条件下显示出显着变化（p值<0.05）。我们的代谢组学研究表明，代谢物对TCS毒性的反应是pH依赖性的。反应的差异可能归因于TCS的生物蓄积能力，在低pH条件下，随着TCS离子化比例的增加，其生物蓄积能力也随之增加。