Development of an external standard method for the high-throughput determination of broadly polar multiclass synthetic dyes in high-sugar, high-fat, and high-protein foods

Simultaneous detection of multiple synthetic dyes in food additives presents a challenge. A high-throughput UPLC-Q-OMS method with purification-free extraction was developed for the simultaneous detection of 30 synthetic dyes across six categories in various foods. The results showed satisfactory separation of the dyes was achieved using a phenyl column, acetonitrile, and a 5 mmol/L ammonium acetate mobile phase. Designing methanol-acetonitrile (2:3, v /v) as a bifunctional extractant can minimize matrix interference and enhance synergistic effects. The LODs of the method were in the range of 0.15–6.28 μg/L, the LOQs were in the range of 0.48–20.52 μg/L with good linearity, and the correlation coefficients (r2) were greater than 0.99. The recoveries at the three spiked levels were in the range of 82.6 %–106.3 %. The technique detected four synthetic dyes within regulatory limits in six out of 66 sample batches (9.09 %), demonstrating its effectiveness in addressing interference and strong applicability.