Simple and reliable method to simultaneously determine urinary 1- and 2-naphthol using in situ derivatization and gas chromatography-mass spectrometry for biological monitoring of naphthalene exposure in occupational health practice

Abstract

Objectives The aim of this study was to develop and validate a simple and reliable gas chromatography‐mass spectrometry (GC‐MS) method to simultaneously determine urinary 1‐naphthol (1‐NAP) and 2‐naphthol (2‐NAP) for biological monitoring of occupational exposure to naphthalene. Methods NAPs were derivatized in situ with acetic anhydride after enzymatic hydrolysis, extracted with n ‐hexane, and analyzed using GC‐MS. Validation of the proposed method was conducted in accordance with US Food and Drug Administration guidance. A final validation was performed by analyzing a ClinChek ® ‐Control for phenolic compounds. Results The linearity of calibration curves was indicated by a high correlation coefficient (>0.999) in the concentration range 1‐100 μg/L for each NAP. The limits of detection and quantification for each NAP were 0.30 and 1.00 μg/L, respectively. The recovery was 90.8%‐98.1%. The intraday and interday accuracies, expressed as the deviation from the nominal value, were 92.2%‐99.9% and 93.4%‐99.9%, respectively. The intraday and interday precision, expressed as the relative standard deviation, was 0.3%‐3.9% and 0.4%‐4.1%, respectively. The ClinChek ® values obtained using our method were sufficiently accurate. Conclusions The proposed method is simple, reliable, and appropriate for routine analyses, and is useful for biological monitoring of naphthalene exposure in occupational health practice.

Removal of 1-naphthol from Water via Photocatalytic Degradation Over N,S-TiO2/ Silica Sulfuric Acid under visible Light

“…To recognize the intermediate compounds created by photo-oxidation reactions of 1-naphthol with N,S-TiO 2 / SSA catalyst, 1-naphthol was extracted from an aqueous environment after irradiation, and the solution was injected into the Gas Chromatography-Mass Spectrometry (GC-MS) device [28]. We used a gas chromatography (Agilent Technologies 7890A model GC) device connected to the mass spectrometer (Agilent Technologies 5975C model) with a 30 m long, 0.25 m in outer diameter, and 0.25 in inner diameter HP5-MS column.…”

1,2-dihydroxynaphthalene as Biomonitoring of Occupational Exposure to Naphthalene

“…According to some studies, the recommended biomonitoring of naphthalene exposure is 1and 2-naphthol in urine (Sams, 2017;Takeuchi et al, 2020;Weiss et al, 2020). However, there are several metabolites that can also be detected and used for biomonitoring of exposure.…”