Determination of UV-327 and its metabolites in human urine using dispersive liquid-liquid microextraction and gas chromatography-tandem mass spectrometry

Presence of benzotriazole ultraviolet stabilizers in human urine

Health exposure to benzotriazole ultraviolet stabilizers (BUVSs) may pose diverse toxic impacts on health. Presently, the occurrence of BUVSs in human urine remains inadequately understood. This study analyzed 13 kinds of BUVSs in human urine (n = 182) from the general Chinese adult participants. Totally, nine BUVSs were measurable in these human urine samples. Among the detected BUVSs, 2-(2H-benzotriazol-2-yl)-p-cresol (UV-P) was the most predominant BUVS in the human urine, with the mean concentration of 1.6 μg/g creatinine ( Collapse

Key Words

• Benzotriazole ultraviolet stabilizers
• Human exposure
• Human urine
• UV-326
• UV-328

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Affiliation(s)

Weili Mao Department of Pharmacy, Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou People's Hospital, Quzhou, Zhejiang, 324000, PR China
Hangbiao Jin Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang, 310032, PR China; Innovation Research Center of Advanced Environmental Technology, Eco-Industrial Innovation Institute ZJUT, Quzhou, Zhejiang, 324400, PR China
Ruyue Guo Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang, 310032, PR China
Kaili Mao Department of Pharmacy, Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou People's Hospital, Quzhou, Zhejiang, 324000, PR China.

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A review of bioanalytical applications of microextraction techniques combined with derivatization

Microextraction techniques have attracted the attention of many researchers working in the field of bioanalysis due to their unique advantages, mainly in downsizing the scale of sample preparation steps. In parallel, analytical derivatization offers a powerful combination in terms of additional sensitivity, selectivity and compatibility with modern separation techniques. The aim of this review is to discuss the most recent advances in bioanalytical sample preparation based on the combination of microextraction and analytical derivatization. Both innovative fundamental reports and analyte-targeted applications are included and discussed. Dispersive liquid-liquid extraction and solid-phase microextraction are the most common techniques that typically combined with derivatization, while the development of novel and greener protocols is receiving substantial consideration in the field of analytical chemistry.

Development and Validation of a DLLME-GC-MS-MS Method for the Determination of Benzotriazole UV Stabilizer UV-327 and Its Metabolites in Human Blood

2-(5-Chloro-benzotriazol-2-yl)-4,6-di-(tert-butyl)phenol (UV-327) is used as an ultraviolet (UV) absorber in plastic materials and coatings. To investigate its metabolism and to assess human exposure, analytical methods are necessary for the determination of UV-327 and its metabolites in human biological specimens. The method thus presented targets the determination of UV-327 and several of its predicted metabolites in blood using protein precipitation, dispersive liquid-liquid microextraction (DLLME) and derivatization. The trimethylsilylated analytes and internal standards are separated by gas chromatography and analyzed with tandem mass spectrometry. The DLLME procedure was optimized with respect to the type and volume of disperser and extraction solvents, the pH value of the sample solution and the addition of salt. During method development, an effective ex vivo lactone/hydroxyl carboxylic acid interconversion was observed for two metabolites, each containing a carboxyl group adjacent to the phenolic hydroxyl group. The analytes resulting from interconversion enabled a more sensitive and reliable determination of the metabolites compared to their native structures. Method validation revealed limits of detection between 0.02 and 0.36 µg/L. The mean relative recovery rates ranged from 91% to 118%. Precision and repeatability were demonstrated by relative standard deviations in the range of 0.6-14.2% and 1.1-13.7%, respectively. The presently described procedure enables the sensitive and robust analysis of UV-327 and its metabolites in human blood and allows the elucidation of the human UV-327 metabolism as well as the assessment of exposure in potentially exposed individuals.

Human metabolism and excretion kinetics of benzotriazole UV stabilizer UV-327 after single oral administration

UV-327 (2-(5-chloro-benzotriazol-2-yl)-4,6-di-(tert-butyl)phenol) is used as an ultraviolet (UV) absorber in plastic products and coatings. Due to its ubiquitous distribution in the environment, human exposure is conceivable. In the study presented herein, initial information on the human in vivo metabolism of UV-327 was obtained by single oral administration to three volunteers. Urine and blood samples were collected up to 72 h after exposure. One study participant additionally donated plasma samples. Maximum blood and plasma levels of UV-327 and its two monohydroxylated metabolites UV-327-6-mOH and UV-327-4-mOH were reached 6 h post-exposure. Almost the entire amount found in blood and plasma samples was identified as UV-327, whereas the two metabolites each accounted for only 0.04% of the total amount, indicating that UV-327 is well-absorbed from the intestine, but only partially metabolized. Plasma to blood ratios of UV-327, UV-327-6-mOH, and UV-327-4-mOH ranged from 1.5 to 1.6. Maximum urinary excretion rates of UV-327, UV-327-6-mOH, UV-327-4-mOH, and UV-327-4 + 6-diOH were reached 9-14 h post-exposure. However, only about 0.03% of the orally administered dose of UV-327 was recovered as UV-327 and its metabolites in urine, indicating that biliary excretion may be the major route of elimination of UV-327 and its hydroxylated metabolites. The present study complements the insight in the complex absorption, distribution, metabolism, and elimination (ADME) processes of benzotriazole UV stabilizers (BUVSs).