| Abstract: | A novel, practical, and environmentally friendly technique, termed concentrated sulfuric acid cleanup and ultrasound-assisted surfactant-enhanced emulsification microextraction (CSAC-UASEM), was combined with HPLC for the preconcentration and determination of five phenolics in water and Arthrospira (Spirulina) platensis samples. The main advantages include that the concentrated sulfuric acid is used to decrease macromolecular interferences prior to microextraction and, unlike dispersive liquid–liquid microextraction procedures, no dispersive organic solvent is required. Chloroform and sodium dodecyl sulfate were used as the extraction solvent and emulsifier, respectively. The algal cell preparation and CSAC-UASEM procedure parameters, including selection of cleanup method, ultrasound power, cell cytocylasis time, type and volume of extraction solvent, extraction temperature, ultrasound-extracted time, and sample pH, were optimized. At the fortification levels of 1.0 and 10.0 µg/L, the enrichment factors of analytes were in the range of 201.38 to 269.24. The percent extraction ranged from 71.57% to 107.42% in environmental Arthrospira-350, -793, and -834 samples, whereas the range was from 74.17% to 106.72% in water samples. The limits of detection (at S/N = 3) were 0.02 to 0.04 µg/L (except for 4-bromobisphenol A of 0.10 µg/L). These values indicate an approximately ten-fold improvement compared with the values reported by other techniques. In summary, the CSAC-UASEM sample preparation technique has great potential in the routine determination of trace phenolics in environmental waters and aquatic biological samples. |
