Gas chromatography (GC) is a commonly used technique in amino acid analysis (AAA). However, one of the requirements of the application of GC for AAA is a need for the polar analytes to be converted into their volatile, thermally stable derivatives. In the last two decades, alkyl chloroformates (RCFs) have become attractive derivatization reagents. The reagents react immediately with most amino acid functional groups in aqueous matrices, and the process can easily be coupled with liquid-liquid extraction of the resulting less polar derivatives into immiscible organic phase. Here we describe a simple protocol for in situ derivatization of amino acids with heptafluorobutyl chloroformate (HFBCF) followed by subsequent chiral as well as nonchiral GC/MS (mass spectrometric) analysis on a respective nonpolar fused silica and an enantioselective Chirasil-Val capillary column.

• MeSH
• Amino Acids blood   chemistry   isolation & purification   MeSH
• Deuterium analysis   chemistry   MeSH
• Liquid-Liquid Extraction instrumentation   methods   MeSH
• Fluorocarbons chemistry   MeSH
• Formates chemistry   MeSH
• Carbon Isotopes analysis   chemistry   MeSH
• Calibration MeSH
• Humans MeSH
• Gas Chromatography-Mass Spectrometry instrumentation   methods   MeSH
• Stereoisomerism MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

The presented work describes the development and validation of a rapid UHPLC-UV method using a fused core particle column with an RP-Amide stationary phase for the separation and quantitative analysis of caffeoylquinic and di-caffeoylquinic acids in green coffee extracts. Three caffeoylquinic acids (3-caffeoylquinic acid, 4-caffeoylquinic acid, and 5-caffeoylquinic acid) and two di-caffeoylquinic acids (1,3-di-caffeoylquinic acid, and 3,5-di-caffeoylquinic acid) were separated and analyzed in 8 min. That was possible due to the unique selectivity of the RP-Amide stationary phase for the analyzed acids. The retention behavior of all analytes under different compositions of the mobile phase on different columns was evaluated in this study. The optimal chromatographic separation was performed using an Ascentis Express RP-Amide (100 × 2.1 mm) fused-core column with a particle size of 2.7 μm at a temperature of 30 °C. For validation of the newly developed method, acetonitrile was used as mobile phase B and 5% formic acid, filtrated through a 0.22 μm filter, was used as mobile phase A. They were delivered at a flow rate of 0.9 mL min-1 according to the elution gradient program. The detection wavelength was set at 325 nm. A solid-liquid extraction with a solution of methanol and a 5% water solution of formic acid (25 + 75 v/v) using an ultrasonic bath was chosen for the preparation of the available commercial samples of food supplements containing a green coffee extract. Recoveries for all analyzed acids were 98.2-101.0% and the relative standard deviation ranged from 0.3% to 1.4% for intra-day and from 0.3% to 3.0% for inter-day repeatability. The limits of detection were in the range of 0.30-0.53 μg mL-1.

• MeSH
• Acetonitriles chemistry   MeSH
• Amides chemistry   MeSH
• Time Factors MeSH
• Liquid-Liquid Extraction instrumentation   methods   MeSH
• Chemistry, Pharmaceutical instrumentation   methods   MeSH
• Coffee chemistry   MeSH
• Quinic Acid analogs & derivatives   analysis   MeSH
• Limit of Detection MeSH
• Porosity MeSH
• Plant Extracts analysis   chemistry   MeSH
• Chromatography, High Pressure Liquid instrumentation   methods   MeSH
• Publication type
• Journal Article MeSH
• Validation Study MeSH