Table 3. MRM transitions in negative mode for derivatized SCFAs.

m/z, mass/charge ratio.

Analyte	Retention time (min)	Ionization mode	MRM transition (m/z)
Acetate	2.9	Negative	194.2	→	137.1
			194.2	→	152.1
Propionate	4.5	Negative	208.1	→	137.1
			208.1	→	165.1
Isobutyrate	6.5	Negative	222.1	→	137.1
			222.1	→	152.1
Butyrate	6.8	Negative	222.1	→	137.1
			222.1	→	152.1
Isovalerate	9.0	Negative	236.2	→	137.1
			236.2	→	152.1
Valerate	9.5	Negative	236.2	→	137.1
			236.2	→	152.1