Quantitative Recovery of Sulfonamides from Chicken Liver, Beef Liver, and Egg Yolk via Modified Supercritical Carbon Dioxide

Solutions of supercritical CO 2 modified with 5, 10, and 20% methanol, ethanol, acetone, and acetonitrile were compared for the extraction of sulfonamides from fortified chicken liver. The results showed both 20% acetone-modified CO 2 and 20% acetonitrile-modified CO 2 were capable of quantitatively extracting sulfamethazine, sulfaquinoxaline, and sulfadimethoxine, whereas 20% ethanol- and 20% methanol-modified CO 2 were found to be less efficient. Acetonitrile-modified CO 2 however, produced fewer chromatographic interferences than acetone, making quantitation easier. Sub-ppm levels of the three analytes were shown to be quantitatively extracted from chicken liver with 20% acetonitrile modifier. Also, quantitative recovery was obtained with spiked beef liver samples employing 20% acetone modifier, and greater than 90% recovery was obtained for two of the three with 20% acetonitrile-modified CO 2, while either 20% acetone- or 20% acetonitrile-modified CO 2 was found to yield quantitative recovery from egg yolk. In contrast to conventional sample preparation procedures no sample cleanup prior to quantitative analysis was required.