Determination of Trigonelline, Nicotinic Acid, and Caffeine in Yunnan Arabica Coffee by Microwave-Assisted Extraction and HPLC with Two Columns in Series

Abstract

A simple, rapid method was developed for simultaneous extraction of trigonelline, nicotinic acid, and caffeine from coffee, and separation by two chromatographic columns in series. The trigonelline, nicotinic acid, and caffeine were extracted with microwave-assisted extraction (MAE). The optimal conditions selected were 3 min, 200 psi, and 120 degrees C. The chromatographic separation was performed with two columns in series, polyaromatic hydrocarbon C18 (250 x 4.6 mm id, 5 microm particle size) and Bondapak NH2 (300 x 3.9 mm id, 5 microm particle size). Isocratic elution was with 0.02 M phosphoric acid-methanol (70 + 30, v/v) mobile phase at a flow rate of 0.8 mL/min. Good recoveries and RSD values were found for all analytes in the matrix. The LOD of the three compounds was 0.02 mg/L, and the LOQ was 0.005% in the matrix. The concentrations of trigonelline, nicotinic acid, and caffeine in instant coffee, roasted coffee, and raw coffee (Yunnan Arabica coffee) were assessed by MAE and hot water extraction; the correlation coefficients between concentrations of the three compounds obtained were close to 1.

Analytical methods applied for the characterization and the determination of bioactive compounds in coffee

“…There was no difference in its level between these beverages [59]. Similar results were found by Liu et al [76] who developed the separation of trigonelline, nicotinic acid and caffeine by HPLC using two chromatographic columns in series.…”

Bioactive Micronutrients in Coffee: Recent Analytical Approaches for Characterization and Quantification

“…In just under 40 s, maximum phenolic content was obtained from spent filter coffee under the influence of low concentrated ethanol [113]. Hongcheng et al [114] have developed a fast MAE method for the simultaneous extraction of TRG, caffeine and nicotinic acid from coffee using a pressure of 200 psi. Other conditions that can affect this procedure include temperature and wattage.…”

“…The application of this system in combination with chemiluminescence detector allowed for increased sensitivity and better selectivity in the determination of antioxidant constituents of three Espresso coffees (“Ristretto,” “Decaffeinato,” and “Volluto”) [132]. Elsewhere, a C-18 and Bondapak NH 2 columns in series were used for the simultaneous determination of TRG, caffeine, and nicotinic acid [114]. This method selected conditions optimal at 120°C and 200 psi, and good separation was achieved in just 3 min, driven by 0.02 M phosphoric acid-methanol (70 : 30, v/v) mobile phase at 0.8 mL/min.…”

Saponificação Assistida Por Micro-Ondas Na Extração De Diterpenos Em Café Arábica Torrado

“…Apesar do aquecimento em micro-ondas ter ocorrido mais rapidamente, não foram observados picos de interferentes/produtos de degradação. Oigman et al 10 e Tsukui et al 15 na extração de diterpenos por metanólise e Liu et al 40 na extração de trigonelina, ácido nicotínico e cafeína em café arábica também não observaram formação de interferentes nas amostras submetidas a irradiação por micro-ondas.…”