A Rapid and Accurate Extraction Procedure for Analysing Free Amino Acids in Meat Samples by GC-MS

Table 1

Ions selected in SIM mode (quantification ions in bold) and retention time (Rt) for the analysis of free amino acids.

Aminoacid	Rt (min)	Ions ()
Alanine	12.86	158, 260, 232
Glycine	13.37	218, 246
Valine	16.60	186, 288, 260
Leucine	17.89	200, 302, 274
Isoleucine	18.98	200, 302, 274
Norleucine (IS)	19.45	200, 147, 274
Proline	20.38	184, 286, 258
Methionine	26.20	218, 320, 292
Serine	26.76	362, 390
Threonine	27.69	404, 376, 303
Phenylalanine	29.56	336, 302, 234
Aspartic acid	30.98	316, 418, 390
Hydroxyproline	31.78	388, 416, 314
Cysteine	32.35	406, 378
Glutamic acid	33.73	432, 330, 272
Asparagine	34.54	417, 302
Lysine	36.14	300, 431, 329
Glutamine	37.14	329, 431, 357, 338
Arginine	38.48	442, 340
Histidine	40.49	196, 489, 440, 338
Tyrosine	41.09	466, 438, 364, 302
Tryptophan	45.10	244, 489, 302
Cystine	50.18	639, 589, 537, 348