Quantification of Trace Volatile Sulfur Compounds in Milk by Solid-Phase Microextraction and Gas Chromatography–Pulsed Flame Photometric Detection

Methanethiol (MeSH) stability and dimethyl disulfide formation measured by pulsed-flame photometric detector (PFPD) in 3.25% fat raw milk spiked with 7μg/kg of MeSH; A) pH = 6.6; B) pH = 2.6. COS = Carbonyl sulfide; H₂S = hydrogen sulfide; CS₂ = carbon disulfide; DMS = dimethyl sulfide; DMDS = dimethyl disulfide; DMTS = dimethyl trisulfide; DMSO = dimethyl sulfoxide; and Me₂SO₄ = dimethyl sulfone.

Concentration of volatile sulfur compounds in commercial milk samples. a) Hydrogen sulfide, b) methanethiol, c) carbon disulfide, and d) dimethyl trisulfide. Raw 1% and Raw 3.25% = raw milk with 1 and 3.25% fat, respectively; UHT 1% and UHT 3.25% = UHT processed milk with 1 and 3.25% fat, respectively; A 0%, A 1%, A 2%, and A 3.25% = pasteurized milk of brand A with 0, 1, 2, and 3.25% fat, respectively; B 0%, B 1%, B 2%, and B 3.25% = pasteurized milk of brand B with 0, 1, 2, and 3.25% fat, respectively.