Table 1.

Preliminary peak assignments related to propylene glycol (PG), vegetable glycerin (VG), polydimethylsiloxane (PDMS), phthalates [including: diethyl phthalate (DEP: C₁₂H₁₄O₄), di-n-butyl phthalate (DBP: C₁₆H₂₂O₄), diisobutyl phthalate (DIBP: C₁₆H₂₂O₄), butyl benzyl phthalate (BBP: C₁₉H₂₀O₄), dicyclohexyl phthalate (DCP: C₂₀H₂₆O₄), di(2-ethylhexyl) phthalate (DEHP: C₂₄H₃₈O₄), di(n-octyl) phthalate (DNOP: C₂₄H₃₈O₄)], and polyethylene glycol (PEG). The −OH peak assignments were distinguished by loss of a neutral water and protonation.

m/z	Assignment	m/z	Assignment	m/z	Assignment
● Propylene Glycol (C 3 H 8 O 2 ) : Vegetable Glycerin (C 3 H 8 O 3 ) Mixture
59.06	[PG-OH] +	117.10	[PG+H2O+Na] +	185.10	[2VG+H] +
75.04	[VG-OH] +	135.10	[2PG-OH] +	211.16	[3PG-OH] +
77.07	[PG+H] +	151.10	[PG+VG-OH] +	227.16	[2PG+VG-OH] +
93.06	[VG+H] +	175.14	[2PG+Na] +	243.16	[PG+2VG-OH] +
◊ Polydimethylsiloxane (C2H6OSi)n (nominal mass difference of repeating unit: +74)
388.18	[(C2H6OSi)5+ NH4]+	536.17	[(C2H6OSi)7+NH4]+	684.21	[(C2H6OSi)9+NH4]+
462.15	[(C2H6OSi)6+NH4]+	610.19	[(C2H6OSi)8+NH4]+	758.20	[(C2H6OSi)10+NH4]+
□ Phthalates
223.10	[DEP+H] +	313.23	[BBP+H] +	391.32	[DEHP+H] +, [DNOP+H] +
279.18	[DBP+H] +, [DIBP+H] +	331.25	[DCP+H] +
▼ Polyethylene Glycol (C 2n H 4n+2 O n+1 ) (nominal mass difference of repeating unit: +44)
300.21	[(C12H26O7)+NH4]+	388.24	[(C16H34O9)+NH4]+
344.22	[(C14H30O8)+NH4]+	432.24	[(C18H38O10)+NH4]+