Miniaturized thermal purge-and-trap device combined with self-calibration colorimetric/SERS dual-model optical sensors for highly rapid and selective detection of sulfur dioxide in wine

Herein, the miniaturized thermal purge-and-trap (MTPT) device combined with self-calibration colorimetric/surface-enhanced Raman spectroscopy (SERS) dual-model optical sensors were designed for effective analysis of sulfur dioxide (SO₂) in wine. The SO₂ can be rapidly separated from wine and enriched by MTPT device, ensuring colorimetric/SERS dual-model optical sensing based on Karl Fischer reaction. The high separation efficiency of miniaturized MTPT device combined with self-calibration of dual-model optical sensors significantly alleviate matrix interference and improve the detection accuracy. The satisfactory linear range of 0.1-200.0 mg/L and 0.1-500.0 mg/L with limit of detection of 0.03 mg/L can be obtained. Finally, the MTPT-colorimetric/SERS method was applied to determine the content of SO₂ in different kinds of wine to verify the practicality. These results provide an ideal strategy in construction of MTPT device combined with self-calibration dual-model optical sensors for quantification of gaseous hazards in complex food samples with high rapidity, anti-interference and accuracy.