Composition Characterization of Fatty Acid Zinc Salts by Chromatographic and NMR Spectroscopic Analyses on Their Fatty Acid Methyl Esters

Table 3

Compositional characterization of two kinds of fatty acids zinc salts A and B by GC-MS analysis on their FAMEs prepared by the optimized conc. HCl/methanol/toluene method.

Peak no.	RT (min)	Fatty acids^a	Total fatty acid composition (%)
			Industrial chemical A		Industrial chemical B
			Conc. HCl/MeOH/toluene^b	NaOH sap/methanolic BF3^c	Conc. HCl/MeOH/toluene^b	NaOH sap/methanolic BF3^c
1	28.18	C12 : 0	1.13 ± 0.18^d	0.85 ± 0.03	2.35 ± 0.03	1.72 ± 0.04
2	33.34	C14 : 0	2.04 ± 0.22	1.62 ± 0.07	0.30 ± 0.01	0.12 ± 0.01
3	38.10	C16 : 0	15.46 ± 0.58	15.05 ± 0.60	5.00 ± 0.05	3.96 ± 0.06
4	40.30	C17 : 0	1.35 ± 0.01	0.86 ± 0.06	—
5	42.46	C18 : 0	27.69 ± 0.45	27.44 ± 1.31	3.02 ± 0.02	2.22 ± 0.03
6	43.39	C18 : 1n9t	—	—	1.12 ± 0.01	0.49 ± 0.07
7	43.81	C18 : 1n9c	45.68 ± 0.49	49.15 ± 2.39	76.39 ± 0.08	77.82 ± 0.96
8	45.75	C18 : 2n6c	6.64 ± 0.05	6.36 ± 0.39	11.81 ± 0.03	10.79 ± 0.16
		Total	100.00	101.33	100.00	97.11

^aFatty acids are designated by number of carbons: number of doubles (C18 : 2n6c means C18 fatty acid with 2 adjacent cis double bonds starting at C6 counting from the methyl group). ^bEsterified directly from fatty acids zinc salts. ^cEsterified from the hydrolysed products (free fatty acids) of fatty acids zinc salts. ^dGC-MS data expressed as means ± standard deviation (n = 3).