A Screening Method for Polycyclic Aromatic Hydrocarbons Determination in Sediments by Headspace SPME with GC–FID

A screening method for polycyclic aromatic hydrocarbons (PAHs) determination in sediment using headspace solid phase microextraction (HS-SPME) with gas chromatography–flame ionization detection was developed. In order to obtain the convenient experimental conditions for HS-SPME extraction an experimental design with two steps was done. 0.2 g of sediment and 85 µm polyacrylate fibre, 80 °C and 120 min were the chosen extractions conditions. The limit of detection (LOD) was from 0.8 ng g⁻¹ (fluoranthene) to 8 ng g⁻¹ (chrysene). The relative standard deviation (RSD) was less than 7.0%. Determination of PAHs in NRC–CNRC–HS–3B reference marine sediment showed good agreement with the certified values. The method was applied in the analysis of ten river and estuary surface sediments from Gipuzkoa (North Spain). PAHs total concentration ranged from 400 to 5,500 ng g⁻¹.

     

Application of response function methodology for the simultaneous determination of potential fragrance allergens and preservatives in personal care products using micellar electrokinetic chromatography

A micellar electrokinetic chromatography method was developed for determination of 15 suspected fragrance allergens and preservatives. The target compounds are widely used as ingredients in many personal care products, and all of them are included in the European Regulation concerning cosmetic products. The method was optimized by using a central composite experimental design and response surface methodology. A modified chromatographic response function was defined to weigh the terms in the response function adequately. After optimization of experimental conditions, a background electrolyte of 100 mM sodium dodecyl sulphate and 24 mM sodium tetraborate and pH 9.0 was selected for the separation of the analytes. The developed methodology was evaluated in terms of linearity, limits of detection and quantification, precision and accuracy, showing appropriate values (i.e., R ²?=?≥0.99 and accuracy of 89–115 %). Finally, applicability of the micellar electrokinetic chromatography method was assessed by successfully quantifying fragrance allergens and preservatives in commercial personal care products. The most commonly found analyte was linalool (48.3 % of samples) followed by benzoic acid (37.6 %). All samples contained at least one of the target compounds, thus confirming the ubiquity of fragrance allergens and preservatives in personal care products.

Optimization and validation of a nonaqueous micellar electrokinetic chromatography method for determination of polycyclic musks in perfumes

A nonaqueous micellar electrokinetic chromatography method was developed for determination of Tonalide®, Galaxolide®, and Traseolide® polycyclic musks (PCMs). These compounds are widely used as fragrance ingredients in cosmetics. The method was optimized by using a three variable Box‐Behnken experimental design and response surface methodology. A modified chromatographic response function was defined in order to adequately weigh the terms in the response function. After optimization of experimental conditions, an electrolyte solution of 195 mM SDS and 40 mM NaH₂PO₄ in formamide was selected for the separation of the three PCMs, and the applied voltage was fixed at 30 kV. The nonaqueous MEKC method was then checked in terms of linearity, limits of detection and quantification, repeatability, intermediate precision and accuracy, providing appropriate values (i.e. RSD values for precision never exceeding 7%, and accuracy 96–107%). Nonaqueous MEKC for determination of the selected compounds was successfully applied to the analysis of commercial perfume samples.