| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1201066 | Journal of Chromatography A | 2015 | 8 Pages |
•The conditions of derivatization of alkylphenols with dansyl chloride were tested.•Improved method provides more reproducible results and lower limits of quantitation.•The high levels of alkylphenols in blank samples affect the result of analysis.•Comparison of the level of alkylphenols in drinking and wastewater was carried out.
The present study describes an effect of reaction condition of pre-column derivatization of alkylphenols (APs): bisphenol A (BPA), 4-tert-octylphenol (4-t-OP), 4-octylphenol (4-OP), 4-n-nonylphenol (4-n-NP), and isomers of 4-nonylphenol (iso-NP) with 5-(dimethylamino) naphthalene-1-sulfonyl chloride (dansyl chloride, DNSC) on their LC–ESI–MS/MS determination in water samples. Chemical derivatization improves the sensitivity and selectivity of LC–MS/MS analysis. In principle, alkylphenols can be analyzed by LC–MS/MS without derivatization. However, pre-column derivatization of APs increases the sensitivity up to 1000 times in comparison with the analysis of underivatized alkylphenols. Reaction conditions affecting formation of the DNSC-derivatives, such as various solvent, reaction temperature, reaction time, DNSC concentration and pH values were tested. The most suitable conditions, in terms of achieving a high sensitivity, resulting from this study are: acetonitrile as reaction solvent, 60 min as reaction time, 60 °C as reaction temperature, pH values 10.5, 0.5 mg mL−1 as DNSC concentration. Calibration curves are linear at least in the range of 1–1000 ng mL−1, limits of detection (LOD) and limits of quantification (LOQ) ranging from 0.02 to 0.25 pg/injection and from 0.08 to 0.83 pg/injection, respectively. The improved procedure was successfully applied for the analysis of APs and BPA in real water samples. The median concentration of BPA and iso-NP obtained in bottled waters was 4.7 ng L−1 and 33.5 ng L−1, respectively. The median concentration of 4-t-OP was 1.3 ng L−1.
