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.磺胺类药物（Sulfonamides, SAs）是一类低成本合成抗菌剂，被广泛应用于兽医与临床医学领域，用于疾病治疗与感染预防。然而，长期接触磺胺类药物可能引发过敏反应等不良反应。本研究旨在探究分散固液微萃取（dispersive solid-liquid microextraction）作为替代方法，用于提取肉类样品中的总磺胺类药物。该方法基于粉色产物（亚胺盐）的生成构建比色反应体系，结合数字化检测手段实现对总磺胺类药物（包括磺胺二甲嘧啶、磺胺二甲氧嘧啶、磺胺噻唑）的定量分析。总磺胺类药物在33~233 μg·kg⁻¹的浓度范围内呈现良好线性响应；在加标浓度为67 μg·kg⁻¹总磺胺类药物的条件下，经11次平行测定得到的变异系数为0.63%，检测限经估算为10 μg·kg⁻¹。对于750 mg的肉类样品，每份样品的试剂消耗量分别为：4-二甲基氨基肉桂醛0.11 mg、十二烷基硫酸钠2.60 mg、正丁醇275 μL，仅产生335 μL的实验废液。此外，本研究开展了加标回收试验，回收率区间为71%~100%，证明了所提方法的正确度。