Analysis of short‐chain aliphatic amines in food and water samples using a near infrared cyanine 1‐(ε‐succinimydyl‐hexanoate)‐1′‐methyl‐3,3,3′,3′‐tetramethyl‐indocarbocyanine‐5,5′‐disulfonate potassium with CE–LIF detection

Abstract

Precolumn derivatization of six short-chain aliphatic amines by a near-infrared dye, 1-(ε-succinimydyl-hexanoate)-1'-methyl-3,3,3',3'-tetramethyl-indocarbocyanine-5,5'- disulfonate potassium (MeCy5-OSu), followed by MEKC-CE-LIF detection has been developed as a method for the determination of aliphatic amines in environmental water and food. Optimum derivatization was operated nicely in pH 9.0 borate buffer at 20°C for 30 min. Well separated peaks were observed with a pH 9.5 BGE containing 10 mmol L⁻¹ phosphoric acid, 20 mmol L⁻¹ SDS, and 7% methanol buffered with 1.0 mol L⁻¹ NaOH. The separation procedure was rapidly achieved within 11 min and the matrix interferences could be effectively eliminated. A linear calibration graph was obtained for 5-200 nmol L⁻¹ analytes with a correlation coefficient in the range 0.9933-0.9995 for amines. This method was successfully utilized to determine aliphatic amines in lake, sewage water, and red wine with recoveries ranging from 96.4 to 105% and the RSDs ranging from 0.9 to 2.9%. Near-infrared, LIF-detector-compatible MeCy5-OSu was proved suitable for the accurate, sensitive, and rapid separation and determination of aliphatic amines in water and food samples.