The standard solutions for L-arginine, L-carnitine, L-glutamic acid, L-isoleucine, L-leucine, L-lysine, L-methionine, LPC (P-16:0), L-phenylalanine, LPC (20:0) (Eicosanoyl-12,12,13,13-D4) and Cell Free Amino Acid Mix (20 AA) (U-D) were prepared with 10% methanol;
The standard solutions of lysophosphatidylcholine (P-16:0) and lysophosphatidylcholine (20:0) (Eicosanoyl-12,12,13,13-D4) were prepared with 50% acetonitrile aqueous solution;
The standard solutions of acetyl-L-carnitine and O-acetyl-L-carnitine (N-methyl-D3) were prepared with 4% hydrochloric acid.