Development of an Environmentally Friendly Extraction Method Using Smartphone-Based Digital Images for the Determination of Total Sulfonamides in Meat Samples

Sulfonamides (SAs) are low-cost synthetic antimicrobials widely used in veterinary and human medicine to treat diseases and prevent infections. However, long periods of exposure to sulfonamides can cause adverse effects such as allergic reactions. This work aims to study dispersive solid-liquid microextraction as an alternative method for extracting total SAs in meat samples. The procedure uses a colorimetric reaction based on the formation of a pink compound (imine salt) to determine total sulfonamides (sulfamethazine, sulfadimethoxine, sulfathiazole) with digital measurements. A linear response was observed between 33-233 μg kg-1 for total sulfonamides, and the coefficient of variation (n = 11; 67 μg kg-1 of total SAs) and the limit of detection were estimated to be 0.63% and 10 μg kg-1, respectively. For a 750 mg meat sample, 0.11 mg of 4-dimethylaminocinnamaldehyde, 2.60 mg of sodium dodecyl sulfate, and 275 μL of 1-butanol were consumed per sample, and consequently, generating only 335 μL of residue. Besides this, addition-recovery tests were performed, resulting in a 71-100% recovery range, indicating the trueness of the proposed method.