Abstract:

In this study， a method for the simultaneous determination of 22 organic ultraviolet absorbers （OUVs） in human serum was established by combining protein precipitation technology （PPT）， efficiency lipid removal technology （ELR） and ultra performance liquid chromatography-tandem mass spectrometry （UPLC-MS/MS）. The OUVs include five benzophenone compounds， five benzotriazole compounds， two cinnamate ester compounds and their three metabolites， two salicylate compounds， two camphor derivative compounds， one triazine compound， one dibenzoylmethane compound and one amino aminobenzoic acid derivative compound. Chromatography was performed using an Acquity BEH C₁₈ column （100 mm×2.1 mm， 1.7 μm）， gradient elution was carried out using methanol-water and methanol-0.1% ammonia water as the mobile phases. Compounds were detected in both positive and negative electrospray ionization （ESI⁺/ESI^‒） modes using multiple reaction monitoring （MRM）， and quantified using stable-isotope internal standards. The experimental results showed that the 22 target compounds exhibited good linear relationships within their respective linear ranges， with the correlation coefficients （r）≥0.999 3. The method detection limits （MDLs） ranged from 0.02 to 0.48 ng/mL， and the method quantification limits （MQLs） ranged from 0.02 to 1.60 ng/mL. At the three spiked levels of low， medium and high， the spiked recoveries of the 22 target analytes ranged from 79.9% to 136.1%， the intra-day precisions were from 1.5% to 25.4%， and the inter-day precisions were from 0.6% to 23.5%. After correction by the stable-isotope internal standard method， the matrix effects of the 22 target analytes in fetal bovine serum were 83.0%‒119.9%. The developed method was successfully used to detect 22 OUVs in 110 human serum samples. With the exception of 3-benzylidene camphor （3-BC）， 2-（2H-benzotriazol-2-yl）-4-methyl-6-（2-propenyl）phenol （UV-9）， 4-methylbenzylidene camphor （4-MBC）， 2，2′-dihydroxy-4-methoxybenzophenone （BP-8）， and 2，4-dihydroxybenzophenone （BP-1）， which were not detected， the remaining 17 substances were detected with overall detection rates of 0.9%–65.5% and the detection levels were <MQL‒11.7 ng/mL. The developed analytical method is simple， convenient， highly sensitive， and is expected to become an effective tool for quantifying 22 OUVs in human serum.

Key words: ultra performance liquid chromatography-tandem mass spectrometry （UPLC-MS/MS）, organic ultraviolet absorbents （OUVs）, serum, protein precipitation technology （PPT）, efficiency lipid removal technology （ELR）, human biomonitoring