Automated on-line column-switching HPLC-MS/MS method with peak focusing for measuring parabens, triclosan, and other environmental phenols in human milk

• Published in: Analytica chimica acta Vol. 622; no. 1; pp. 150 - 156
• Main Authors: Ye, Xiaoyun, Bishop, Amber M., Needham, Larry L., Calafat, Antonia M.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.08.2008; Elsevier
• Subjects: Analytical chemistry; Applied sciences; Chemistry; Chromatographic methods and physical methods associated with chromatography; Chromatography, High Pressure Liquid - instrumentation; Chromatography, High Pressure Liquid - methods; Environment; Exact sciences and technology; Female; Global environmental pollution; HPLC-MS/MS; Humans; Milk; Milk, Human - chemistry; Online Systems - instrumentation; Other chromatographic methods; Parabens; Parabens - analysis; Parabens - chemistry; Phenols; Phenols - analysis; Phenols - chemistry; Pollution; Solid Phase Extraction; Spectrometric and optical methods; Tandem Mass Spectrometry - instrumentation; Tandem Mass Spectrometry - methods; Triclosan; Triclosan - analysis; Triclosan - chemistry; Phenols; HPLC-MS/MS; Triclosan; Parabens; Milk; Solid phase extraction; Column switching; Data storage; HPLC chromatography; Chemical enrichment; Ester; Accuracy; Alkyl 4-hydroxybenzoate; Detection limit; Sampling; Variation coefficient; Drug; Stability; Foodstuff; Automatic processing; Bisphenol A; Reproducibility; Mass spectrometry MS/MS; Human milk; Environment
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/j.aca.2008.05.068

Parabens (esters of p-hydroxybenzoic acid) and triclosan are widely used as preservatives and antimicrobial agents, respectively, in personal care products, pharmaceuticals, and food processing. Because of their widespread use and potential risk to human health, assessing human exposure to these compounds in breastfed infants is of interest. We developed a sensitive method, using a unique on-line solid-phase extraction-high performance liquid chromatography-tandem mass spectrometry system with peak focusing feature, to measure in human milk the concentrations of five parabens (methyl-, ethyl-, propyl-, butyl-, and benzyl parabens), triclosan, and six other environmental phenols: bisphenol A (BPA); ortho-phenylphenol (OPP); 2,4-dichlorophenol; 2,5-dichlorophenol; 2,4,5-trichlorophenol; and 2-hydroxy-4-methoxybenzophenone (BP-3). The method, validated by use of breast milk pooled samples, shows good reproducibility (inter-day coefficient of variations ranging from 3.5% to 16.3%) and accuracy (spiked recoveries ranging from 84% to 119% at four spiking levels). The detection limits for most of the analytes are below 1 ng mL −1 in 100 μL of milk. We tested the usefulness of the method by measuring the concentrations of these twelve compounds in four human milk samples. We detected methyl paraben, propyl paraben, triclosan, BPA, OPP, and BP-3 in some of the samples tested. The free species of these compounds appear to be the most prevalent in milk. Nevertheless, to demonstrate the utility of these measures for exposure and risk assessment purposes, additional data about sampling and storage of the milk, and on the stability of the analytes in milk, are needed.