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Rangel Silva A, Almeida PJ, Santos JR. Multiple pulse amperometry in low pressure chromatography for parallel determination of oxidizable and reducible compounds. Analysis of a green coffee extract as a case study. Talanta 2024; 266:125016. [PMID: 37541005 DOI: 10.1016/j.talanta.2023.125016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 07/26/2023] [Accepted: 07/29/2023] [Indexed: 08/06/2023]
Abstract
In this paper, the determination of both oxidizable and reducible compounds within a single chromatographic run is exploited for the first time, using a low-pressure chromatographic system and multiple pulse amperometric detection. The case study selected focussed on the analysis of green coffee extracts. The separation of the compounds was carried out using a 1-cm length monolithic column and an eluent prepared by mixing an aqueous solution of an ion-pair reagent, perfluoroheptanoic acid (PFHpA), and acetonitrile. The parallel determination of oxidizable and reducible compounds was performed by application of two consecutive pulses, E1 = +1.6 V and E2 = -1.5 V. At anodic conditions, the chromatographic peaks for 5-caffeoylquinic acid (5-CQA), caffeine and 5-feruloylquinic acid (5-FQA) were detected, while at cathodic conditions, a chromatographic peak was ascribed for trigonelline. In the developed methodology, the use of multiple pulse amperometry provided better sensitivity if compared to previously described amperometric methodologies determining either oxidizable or reducible compounds. Detection limits for the referred compounds of ca. 1 × 10-5 mol L-1, an analysis rate of 12 h-1 and an acetonitrile consumption of 0.07 mL per analysis were achieved. The approach presented demonstrates the possibility of combining low pressure chromatographic systems and multiple pulse amperometry, in the development of new, low-cost and fast methodologies for multi-analyte determinations.
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Affiliation(s)
- Alexandra Rangel Silva
- REQUIMTE/LAQV - Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Porto, Portugal
| | - Paulo J Almeida
- REQUIMTE/LAQV - Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Porto, Portugal
| | - João Rodrigo Santos
- REQUIMTE/LAQV - Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Porto, Portugal.
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Portillo OR. El procesamiento del grano de café. Del tueste a la infusión. BIONATURA 2022. [DOI: 10.21931/rb/2022.07.03.18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
El café es una de las bebidas más consumidas en el mundo y su popularidad no está basada en su valor nutricional o sus potenciales beneficios a la salud, si no en su sabor placentero y las propiedades estimulantes de la cafeína. Esto es respaldado por las últimas estadísticas publicadas por la Organización Internacional del Café (ICO, por sus siglas en inglés) según la cual aproximadamente 1.4 billones de tazas de café son consumidas diariamente además del hecho de que la taza de consumo global se ha duplicado en los últimos 50 años por causa de la apertura de nuevos mercados.
La amplia aceptación del café está ligada a sus propiedades sensoriales las cuales a su vez están fuertemente influenciadas por una cadena de eventos que inician desde la cosecha y las practicas postcosecha (i.e., fermentación, lavado, secado, tamizado, eliminación de granos defectuosos y almacenamiento), seguidas por el tueste, molido y empacado del producto para su posterior comercialización. No obstante, existen otros factores que también afectan las propiedades organolépticas de la bebida tales como, pero no limitado a: el pH y temperatura del agua, las mezclas realizadas antes o después del tueste, la especie y/o variedad de café, las adulteraciones, la incorporación de aditivos, el método de preparación de la bebida, el tipo de recipiente en el que se sirve la infusión, entre otros.
El presente artículo presenta una breve descripción de los factores que afectan la calidad de la taza relacionados con el procesamiento del grano oro del café. Sin embargo, aunque los factores ya mencionados son tomados en consideración por los catadores, para fines comerciales, la calidad del café está y siempre estará en manos del consumidor. Después de todo la mejor prueba es cuando la persona lo prueba.
Palabras clave: organoléptica, perfil de tueste, endotérmica, exotérmico, ma-croscópica, microscópica, reacción Maillard, caramelización.
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Affiliation(s)
- Ostilio R. Portillo
- Facultad de Ingeniería, Universidad Nacional Autónoma de Honduras, (UNAH), Tegucigalpa, Honduras
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Nussbaum L, Llamas N, Chocholouš P, Rodríguez MS, Sklenářová H, Solich P, Di Anibal C, Acebal CC. A simple method to quantify azo dyes in spices based on flow injection chromatography combined with chemometric tools. JOURNAL OF FOOD SCIENCE AND TECHNOLOGY 2022; 59:2764-2775. [PMID: 35734112 PMCID: PMC9207011 DOI: 10.1007/s13197-021-05299-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 06/09/2021] [Accepted: 10/17/2021] [Indexed: 06/15/2023]
Abstract
UNLABELLED Para Red (PR) and Sudan dyes have been illegally used as colorants to adulterate certain foods by enhancing their red/orange colour. In addition, they are toxic and carcinogenic. This work presents the development of a simple flow injection chromatographic method combined with chemometric tools to perform the determination of PR, Sudan I (SI) and Sudan II (SII) in food samples. The flow chromatographic system consisted of a low-pressure manifold coupled to a reverse phase monolithic column. A Partial Least Square (PLS) model was applied to resolve overlapped absorption spectra registered for each dye at the corresponding retention time. The relative errors of calibration (RMSECV, %) were 0.49, 0.85 and 0.23, and the relative errors of prediction (RMSEP, %) were 1.12, 0.75 and 0.33 for PR, SI and SII, respectively. The residual predictive deviation (RPD) values obtained were higher than 3.00 for all analytes. The method was successfully applied to quantify the dyes in six different commercial spices samples. The results were compared with the HPLC reference method concluding that there were no significant differences at the studied confidence level (α = 0.05). The proposed method can be used to rapidly determine the analytes in a simple, reliable, low-cost and environmentally-friendly manner. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s13197-021-05299-8.
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Affiliation(s)
- Luana Nussbaum
- Departamento de Química, INQUISUR, Universidad Nacional del Sur (UNS)-CONICET, Av. Alem 1253, 8000 Bahía Blanca, Argentina
| | - Natalia Llamas
- Departamento de Química, INQUISUR, Universidad Nacional del Sur (UNS)-CONICET, Av. Alem 1253, 8000 Bahía Blanca, Argentina
| | - Petr Chocholouš
- Department of Analytical Chemistry, Faculty of Pharmacy, Charles University, 500 05 Hradec Králové, Czechia
| | - María Susana Rodríguez
- Departamento de Química, INQUISUR, Universidad Nacional del Sur (UNS)-CONICET, Av. Alem 1253, 8000 Bahía Blanca, Argentina
| | - Hana Sklenářová
- Department of Analytical Chemistry, Faculty of Pharmacy, Charles University, 500 05 Hradec Králové, Czechia
| | - Petr Solich
- Department of Analytical Chemistry, Faculty of Pharmacy, Charles University, 500 05 Hradec Králové, Czechia
| | - Carolina Di Anibal
- Departamento de Química, INQUISUR, Universidad Nacional del Sur (UNS)-CONICET, Av. Alem 1253, 8000 Bahía Blanca, Argentina
| | - Carolina C. Acebal
- Departamento de Química, INQUISUR, Universidad Nacional del Sur (UNS)-CONICET, Av. Alem 1253, 8000 Bahía Blanca, Argentina
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Yue ZX, Gu YX, Yan TC, Li MH, Zheng H, Cao J. Ion pair-based mobile phase additives to improve the separation of alkaloids in supercritical fluid chromatography. J Pharm Biomed Anal 2022; 208:114467. [PMID: 34775191 DOI: 10.1016/j.jpba.2021.114467] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 10/07/2021] [Accepted: 11/02/2021] [Indexed: 01/05/2023]
Abstract
In this study, a supercritical fluid chromatography (SFC) method based on ion pair reagents was used to separate alkaloids. The chromatographic parameters, including the stationary phase, additive type, additive concentration, outlet pressure, temperature and flow rate, were optimized. Baseline separation was completed in 20 min on an Agilent Pursuit 5 PFP column (4.6 × 150 mm) using carbon dioxide as the mobile phase and 7.5 mM sodium 1-pentanesulfonate as an additive with gradient elution at 140 bar, 60 °C, and a flow rate of 1.5 mL/min. The retention rate and resolution of the analytes were satisfactory. The limits of detection were 27.04-298.03 ng/mL, and the limits of quantification were 90.15-993.42 ng/mL. The recoveries of low and high concentrations were 77.46-111.86% and 83.84-111.00%, respectively. This ion pair additive greatly improved the separation efficiency of alkaloids. Consequently, this SFC method was successfully applied to the separation of alkaloids from Rhizoma corydalis.
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Affiliation(s)
- Zi-Xuan Yue
- College of Pharmacy, Hangzhou Normal University, Hangzhou 311121, PR China
| | - Yu-Xin Gu
- College of Pharmacy, Hangzhou Normal University, Hangzhou 311121, PR China
| | - Tian-Ci Yan
- College of Pharmacy, Hangzhou Normal University, Hangzhou 311121, PR China
| | - Min-Hui Li
- College of Pharmacy, Hangzhou Normal University, Hangzhou 311121, PR China
| | - Hui Zheng
- College of Material Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou 311121, PR China.
| | - Jun Cao
- College of Pharmacy, Hangzhou Normal University, Hangzhou 311121, PR China; College of Material Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou 311121, PR China.
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Screening of Antioxidant Compounds in Green Coffee by Low-Pressure Chromatography with Amperometric Detection. FOOD ANAL METHOD 2021. [DOI: 10.1007/s12161-021-02037-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Zhao X, Yang D, Pang Y, Shen X. Quaternary ammonium salt ion pair reagent sensitizing for determination of fluorescence whitening agent 85 in paper food packaging. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2020; 231:118125. [PMID: 32058917 DOI: 10.1016/j.saa.2020.118125] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2019] [Revised: 02/01/2020] [Accepted: 02/01/2020] [Indexed: 06/10/2023]
Abstract
Fluorescent whitening agents (FWAs) are added to food packaging during manufacture to improve the whiteness and brightness. It is of great significance to develop a fast and sensitive FWAs detection method because their potential hazards to human health. Herein, we found that the quaternary ammonium salt ion pair reagents could enhance the fluorescence of FWAs, and then developed a fluorescent determination method for FWA 85 in paper food packaging. Under the optimized conditions, the linear range for the determination of FWA 85 was 5-200 ng/mL (R2 = 0.9996). The limit of detection was 1.20 ng/mL (S/N = 3) and the limit of quantitation was 3.99 ng/mL. The analytical feasibility was investigated further via determination of FWA 85 in paper food packing, which shows the recoveries were varied from 83.84% to 115.29% with RSDs from 1.64% to 7.22%. The method provides a new quaternary ammonium salt ion pair reagent sensitization for the detection of FWAs in paper food packaging.
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Affiliation(s)
- Xiangyu Zhao
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, PR China
| | - Dianqi Yang
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, PR China
| | - Yuehong Pang
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, PR China
| | - Xiaofang Shen
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, PR China.
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