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KOTANI A, WATANABE J, MACHIDA K, YAMAMOTO K, HAKAMATA H. Determination of Amino Acidity in Japanese Sake Based on the Voltammetric Measurement of Surplus Acid by Quinone Reduction. ELECTROCHEMISTRY 2022. [DOI: 10.5796/electrochemistry.22-00108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Akira KOTANI
- Department of Analytical Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences
| | - Jumpei WATANABE
- Department of Analytical Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences
| | - Koichi MACHIDA
- Department of Analytical Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences
| | - Kazuhiro YAMAMOTO
- Department of Analytical Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences
| | - Hideki HAKAMATA
- Department of Analytical Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences
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Ching CB, Abdullah J, Yusof NA. Voltammetric determination of palmitic acid by electrode modified with reduced graphene oxide. JOURNAL OF FOOD SCIENCE AND TECHNOLOGY 2022; 59:1053-1062. [PMID: 35153325 PMCID: PMC8814192 DOI: 10.1007/s13197-021-05109-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 04/12/2021] [Accepted: 04/14/2021] [Indexed: 11/29/2022]
Abstract
Palm oil is one of the most produced and traded vegetable oils in the world recently. The quality of palm oil is very important to be examined and one of the quality indices is free fatty acid (FFA) content. Thus, in this study, an electrochemical technique for the determination of FFA as alternative to conventional method (titration method) has been explored. The electrochemical method was developed based on electrochemically reduced graphene oxide (rGO) deposited onto screen printed carbon electrode (SPCE) via drop-casting technique. The modified electrode was characterized by physico-chemical and electrochemical methods, respectively. The voltammetric behaviour of 2-methyl-1,4-naphthaquinone (VK3) in the presence of palmitic acid at the modified electrode was investigated in an acetonitrile/water (3:1) mixture containing 2.5 M lithium perchlorate (LiClO4). The electrochemical detection of palmitic acid was based on the voltammetric reduction of VK3 to form corresponding hydroquinone which is proportional to the concentration of palmitic acid. Under optimum condition, the developed method showed a good linear relationship in the concentration ranging from 0.192 mM to 0.833 mM with the detection limit of 0.079 mM. The developed sensor illustrates high sensitivity and rapid detection towards determination of FFA content in palm oil.
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Affiliation(s)
- Chin Boon Ching
- Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Selangor Malaysia
| | - Jaafar Abdullah
- Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Selangor Malaysia
- Institute of Advanced Technology, University Putra Malaysia, 43400 Serdang, Selangor Malaysia
| | - Nor Azah Yusof
- Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Selangor Malaysia
- Institute of Advanced Technology, University Putra Malaysia, 43400 Serdang, Selangor Malaysia
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KOTANI A, MIYAGUCHI Y, MIYASHITA N, KUSU F, TAKAMURA K, HAKAMATA H. HPLC with Electrochemical Detection Systems for Quantitative Analysis of Functional Components in Foods. BUNSEKI KAGAKU 2021. [DOI: 10.2116/bunsekikagaku.70.415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Akira KOTANI
- Department of Analytical Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences
| | - Yuji MIYAGUCHI
- Department of Analytical Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences
| | - Naoto MIYASHITA
- Department of Analytical Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences
| | - Fumiyo KUSU
- Department of Analytical Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences
| | - Kiyoko TAKAMURA
- Department of Analytical Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences
| | - Hideki HAKAMATA
- Department of Analytical Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences
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Wang Y, Wang J, Pang J, Zhang L, Xu W, Shao C. Introduction of protonic potential of Brønsted−Lowry acids and bases to the quantification of the energy of proton translocation and elucidation of oxidative phosphorylation. J Electroanal Chem (Lausanne) 2020. [DOI: 10.1016/j.jelechem.2020.113909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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5
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Xu W, Shao C, Pang J, Jiang Y, Han Y, Wang J. Electrochemical method of pyrophosphate determination by quinone reduction. Electrochim Acta 2019. [DOI: 10.1016/j.electacta.2019.01.096] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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6
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Kotani A, Kitamura K, Kusu F, Yamamoto K, Hakamata H. Voltammetric Determination of Amino Acids Based on the Measurement of Reduction Prepeak of Quinone Caused by Surplus Acid after Neutralization. ELECTROANAL 2018. [DOI: 10.1002/elan.201800480] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Akira Kotani
- Department of Analytical Chemistry, School of Pharmacy; Tokyo University of Pharmacy and Life Sciences
| | - Kanae Kitamura
- Department of Analytical Chemistry, School of Pharmacy; Tokyo University of Pharmacy and Life Sciences
| | - Fumiyo Kusu
- Department of Analytical Chemistry, School of Pharmacy; Tokyo University of Pharmacy and Life Sciences
| | - Kazuhiro Yamamoto
- Department of Analytical Chemistry, School of Pharmacy; Tokyo University of Pharmacy and Life Sciences
| | - Hideki Hakamata
- Department of Analytical Chemistry, School of Pharmacy; Tokyo University of Pharmacy and Life Sciences
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Li M, Xu L, Yu X, Chen J, Liu X. Novel method based on fourier transform infrared spectroscopy for determining fat acidity of cereal products. INTERNATIONAL JOURNAL OF FOOD PROPERTIES 2018. [DOI: 10.1080/10942912.2017.1381113] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Mengjun Li
- College of Food Science and Engineering, Northwest A&F University, Yangling Shaanxi, P. R. China
| | - Lirong Xu
- College of Food Science and Engineering, Northwest A&F University, Yangling Shaanxi, P. R. China
| | - Xiuzhu Yu
- College of Food Science and Engineering, Northwest A&F University, Yangling Shaanxi, P. R. China
| | - Jia Chen
- College of Food Science and Engineering, Northwest A&F University, Yangling Shaanxi, P. R. China
| | - Xiaoli Liu
- College of Food Science and Engineering, Northwest A&F University, Yangling Shaanxi, P. R. China
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Yanai H, Takahashi R, Takahashi Y, Kotani A, Hakamata H, Matsumoto T. 2-(Pyridinium-1-yl)-1,1-bis(perfluoroalkylsulfonyl)ethan-1-ide: A Practical Reagent for Synthesis of Strongly Acidic 1,1-Bis(perfluoroalkylsulfonyl)alkanes. Chemistry 2017; 23:8203-8211. [DOI: 10.1002/chem.201700515] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Indexed: 11/11/2022]
Affiliation(s)
- Hikaru Yanai
- School of Pharmacy; Tokyo University of Pharmacy and Life Sciences; 1432-1 Horinouchi, Hachioji Tokyo 192-0392 Japan
| | - Ryuta Takahashi
- School of Pharmacy; Tokyo University of Pharmacy and Life Sciences; 1432-1 Horinouchi, Hachioji Tokyo 192-0392 Japan
| | - Yoichi Takahashi
- School of Pharmacy; Tokyo University of Pharmacy and Life Sciences; 1432-1 Horinouchi, Hachioji Tokyo 192-0392 Japan
| | - Akira Kotani
- School of Pharmacy; Tokyo University of Pharmacy and Life Sciences; 1432-1 Horinouchi, Hachioji Tokyo 192-0392 Japan
| | - Hideki Hakamata
- School of Pharmacy; Tokyo University of Pharmacy and Life Sciences; 1432-1 Horinouchi, Hachioji Tokyo 192-0392 Japan
| | - Takashi Matsumoto
- School of Pharmacy; Tokyo University of Pharmacy and Life Sciences; 1432-1 Horinouchi, Hachioji Tokyo 192-0392 Japan
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Differential Pulse Voltammetric Determination of Lactic Acid in Yogurts Based on Reduction of 1,4-Benzoquinone. FOOD ANAL METHOD 2017. [DOI: 10.1007/s12161-017-0883-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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10
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Attenuated Total Reflectance Fourier transform infrared spectroscopy for determination of Long Chain Free Fatty Acid concentration in oily wastewater using the double wavenumber extrapolation technique. Talanta 2017; 165:526-532. [DOI: 10.1016/j.talanta.2017.01.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 01/02/2017] [Accepted: 01/03/2017] [Indexed: 11/24/2022]
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Mahesar SA, Shah SN, Mahesar AW, Kandhro AA, Khaskheli AR, Menghwar P, Sherazi STH. A chemometric approach for the quantification of free fatty acids in cottonseed oil by Fourier transform infrared spectroscopy. INTERNATIONAL JOURNAL OF FOOD PROPERTIES 2016. [DOI: 10.1080/10942912.2016.1223129] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Sarfaraz Ahmed Mahesar
- National Centre of Excellence in Analytical Chemistry, University of Sindh, Jamshoro, Pakistan
| | - Syed Nasrullah Shah
- National Centre of Excellence in Analytical Chemistry, University of Sindh, Jamshoro, Pakistan
| | - Abdul Waheed Mahesar
- Institute of Information and Communication Technology, University of Sindh, Jamshoro, Pakistan
| | - Aftab Ahmed Kandhro
- Dr. M.A. Kazi Institute of Chemistry, University of Sindh, Jamshoro, Pakistan
| | - Abdul Rauf Khaskheli
- Department of Pharmacy, Shaheed Mohtarma Benazir Bhutto Medical University, Larkana, Pakistan
| | - Pertab Menghwar
- National Centre of Excellence in Analytical Chemistry, University of Sindh, Jamshoro, Pakistan
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Baldo MA, Oliveri P, Simonetti R, Daniele S. A novel electroanalytical approach based on the use of a room temperature ionic liquid for the determination of olive oil acidity. Talanta 2016; 161:881-887. [DOI: 10.1016/j.talanta.2016.09.045] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 09/14/2016] [Accepted: 09/16/2016] [Indexed: 11/29/2022]
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13
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Yanai H. Chemistry of Fluorinated Carbon Acids: Synthesis, Physicochemical Properties, and Catalysis. Chem Pharm Bull (Tokyo) 2015; 63:649-62. [PMID: 26329858 DOI: 10.1248/cpb.c15-00487] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The bis[(trifluoromethyl)sulfonyl]methyl (Tf2CH; Tf=SO2CF3) group is known to be one of the strongest carbon acid functionalities. The acidity of such carbon acids in the gas phase is stronger than that of sulfuric acid. Our recent investigations have demonstrated that this type of carbon acids work as novel acid catalysts. In this paper, recent achievements in carbon acid chemistry by our research group, including synthesis, physicochemical properties, and catalysis, are summarized.
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Affiliation(s)
- Hikaru Yanai
- School of Pharmacy, Tokyo University of Pharmacy and Life Sciences
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14
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Comparing a novel voltammetric method with a standardized method for quality control of biodiesel. J IND ENG CHEM 2015. [DOI: 10.1016/j.jiec.2014.09.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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15
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Direct FTIR Analysis of Free Fatty Acids in Edible Oils Using Disposable Polyethylene Films. FOOD ANAL METHOD 2014. [DOI: 10.1007/s12161-014-9963-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Sato RT, de Jesus Coelho Castro R, de Castro Barra PM, de Oliveira MAL. Rapid separation of free fatty acids in vegetable oils by capillary zone electrophoresis. PHYTOCHEMICAL ANALYSIS : PCA 2014; 25:241-246. [PMID: 24453169 DOI: 10.1002/pca.2499] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Revised: 11/20/2013] [Accepted: 11/26/2013] [Indexed: 06/03/2023]
Abstract
INTRODUCTION Olive oil is a very important product to human health since it inhibits formation of free radicals, tumour growth, lesions and inflammatory substances. High concentrations of free fatty acids in olive oils results in lipid deterioration due to oxidative or hydrolytic rancidity. OBJECTIVE To optimise an alternative capillary zone electrophoresis methodology, under ultraviolet indirect detection and to determine free fatty acids in edible vegetable oils without derivatisation steps in sample preparation. METHODS The condition used consisted of 15 mm NaH2 PO4 -Na2 HPO4 at pH ~6.86, 4.0 mm of sodium dodecybenzenesulphonate, 8.3 mm of Brij 35®, 45% v/v of acetonitrile and 2.1% of 1-octanol, injection at 12.0 mbar of pressure for 4 s, +19 kV of applied voltage and indirect detection at 224 nm, within an analysis time of 11 min. RESULTS The capillary zone electrophoresis method was successfully applied to determination of free fatty acids in extra virgin olive oil, virgin olive oil and soybean oil samples. The comparison with the official volumetric titration method showed no significant difference within the 95% confidence interval. CONCLUSION The main advantage to the proposed method is the possibility to observe the individual amount of the free fatty acids, which would be useful for researchers interested in studying the effect of the free fatty acids profile on oxidative process in food.
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Affiliation(s)
- Renata Takabayashi Sato
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Juiz de Fora, Cidade Universitária CEP, 36036-330, Juiz de Fora, MG, Brazil
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Yanai H, Taguchi T. Synthesis and Catalysis of Strong Carbon Acids Containing Bis(triflyl)methyl Group. J SYN ORG CHEM JPN 2014. [DOI: 10.5059/yukigoseikyokaishi.72.158] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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18
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Yanai H, Fujita M, Takahashi A, Zhang M, Mishima M, Kotani A, Matsumoto T, Taguchi T. Synthesis of δ-oxo-1,1-bis(triflyl)alkanes and their acidities. Molecules 2013; 18:15531-40. [PMID: 24352012 PMCID: PMC6269671 DOI: 10.3390/molecules181215531] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 12/03/2013] [Accepted: 12/11/2013] [Indexed: 11/22/2022] Open
Abstract
The reaction of 1,1-bis(triflyl)ethylene generated in situ with enolizable carbonyls yielded δ-oxo-1,1-bis(triflyl)alkane derivatives. Their acidities in both the gas and solution phases were determined.
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Affiliation(s)
- Hikaru Yanai
- School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan.
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da Silva Figueiredo E, de Castro Vieira E, de Siqueira Cavalcanti EH, D'Elia E. Validation of a New Analytical Method for the Measurement of Free Fatty Acids in Biodiesel. ELECTROANAL 2013. [DOI: 10.1002/elan.201200513] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Yanai H, Yoshino T, Fujita M, Fukaya H, Kotani A, Kusu F, Taguchi T. Synthesis, Characterization, and Applications of Zwitterions Containing a Carbanion Moiety. Angew Chem Int Ed Engl 2012; 52:1560-3. [DOI: 10.1002/anie.201208809] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Indexed: 11/11/2022]
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Yanai H, Yoshino T, Fujita M, Fukaya H, Kotani A, Kusu F, Taguchi T. Synthesis, Characterization, and Applications of Zwitterions Containing a Carbanion Moiety. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201208809] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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22
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A New Method for Determining Free Fatty Acid Content in Edible Oils by Using Electrical Conductivity. FOOD ANAL METHOD 2012. [DOI: 10.1007/s12161-012-9399-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Yanai H, Ogura H, Fukaya H, Kotani A, Kusu F, Taguchi T. An Effective Method to Introduce Carbon Acid Functionality: 2,2-Bis(trifluoromethanesulfonyl)ethylation Reaction of Arenes. Chemistry 2011; 17:11747-51. [DOI: 10.1002/chem.201102023] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Indexed: 11/11/2022]
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Takamura K. ELECTROCHEMISTRY 2010; 78:705-713. [DOI: 10.5796/electrochemistry.78.705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Kotani A, Miyaguchi Y, Kohama M, Ohtsuka T, Shiratori T, Kusu F. Determination of short-chain fatty acids in rat and human feces by high-performance liquid chromatography with electrochemical detection. ANAL SCI 2009; 25:1007-11. [PMID: 19667478 DOI: 10.2116/analsci.25.1007] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A simple method for determining short-chain fatty acids (SCFAs) in rat and human feces was developed using high-performance liquid chromatography with electrochemical detection (HPLC-ECD). A two-channel HPLC-ECD system was fabricated using an ion exclusion column and an electrochemical detector with a glassy carbon working electrode. Aqueous solutions of 0.1 mM HClO(4) and of ethanol containing 2-methyl-1,4-naphthoquinone served as a mobile phase and a quinone solution, respectively. Peak areas for lactic, acetic, propionic, butyric, isovaleric, and valeric acids at a detection potential of -0.9 V vs. an Ag/AgCl electrode showed a linear relationship with the acid amount in the range 0.1 to 40 nmol. Standard acids at 4 nmol were determined ten times with relative standard deviations (RSD) of less than 2.0%. The analytical results of healthy human feces were measured within 35 min. RSD (n = 5) in all SCFAs were less than 2.7%, and recoveries of SCFAs were more than 92%. The present method was characterized by reproducibility with the simple and rapid procedure without derivatization of analytes, and it has the potential for clinical and biomedical applications.
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Affiliation(s)
- Akira Kotani
- Department of Analytical Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Hachioji, Japan.
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Voltammetric behavior of trolox in the presence of amino acid in unbuffered dimethylsulfoxide. J Electroanal Chem (Lausanne) 2008. [DOI: 10.1016/j.jelechem.2008.07.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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27
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Boudalis AK, Policand X, Sournia-Saquet A, Donnadieu B, Tuchagues JP. Synthesis, spectroscopic, structural and electrochemical studies of carboxyl substituted 1,4-naphthoquinones. Inorganica Chim Acta 2008. [DOI: 10.1016/j.ica.2007.02.027] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Li SG, Zhang H, Xue WT. A novel method for the determination of acid value of vegetable oils. EUR J LIPID SCI TECH 2007. [DOI: 10.1002/ejlt.200700058] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Balesteros MR, Tavares MFM, Ribeiro SJL, Polachini FC, Messaddeq Y, de Oliveira MAL. Determination of olive oil acidity by CE. Electrophoresis 2007; 28:3731-6. [DOI: 10.1002/elps.200700507] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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30
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Wan PJ, Dowd MK, Thomas AE, Butler BH. Trimethylsilyl Derivatization/Gas Chromatography as a Method to Determine the Free Fatty Acid Content of Vegetable Oils. J AM OIL CHEM SOC 2007. [DOI: 10.1007/s11746-007-1101-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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31
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Rafiee M, Nematollahi D. Voltammetry of Electroinactive Species Using Quinone/Hydroquinone Redox: A Known Redox System Viewed in a New Perspective. ELECTROANAL 2007. [DOI: 10.1002/elan.200703864] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Sherazi STH, Mahesar SA, Bhanger MI, van de Voort FR, Sedman J. Rapid determination of free fatty acids in poultry feed lipid extracts by SB-ATR FTIR spectroscopy. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2007; 55:4928-32. [PMID: 17530766 DOI: 10.1021/jf063554f] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
A simple, rapid, and reproducible method has been developed for the quantitative determination of free fatty acid (FFA) content in lipids extracted from poultry feeds by Fourier transform infrared (FTIR) spectroscopy with the use of a single-bounce attenuated total reflectance (SB-ATR) accessory. An FTIR calibration curve was prepared by gravimetrically adding oleic acid (15-37%) to pure refined, bleached, and deodorized (RBD) canola oil and measuring the area of the COOH absorption band at 1710 cm-1. The oil from each of 12 poultry feed formulations was extracted using conventional Soxhlet extraction, and after evaporation of the solvent, the FFA content was determined by the conventional AOCS titrimetric procedure and by the SB-ATR/FTIR method. The SB-ATR/FTIR FFA predictions were related to those determined by the AOCS titrimetric method by linear regression, producing an R value of 0.999 and a SD of +/-0.28% FFA. Time-course spectra collected as lipids extracted into hexane indicated that a 15 min extraction was adequate to obtain a representative sample for FFA determination, with further extraction resulting in little, if any, change in the proportion of FFA in the lipid extract. Only a small volume of the hexane extract ( approximately 20 mL) yielded sufficient material for the SB-ATR/FTIR analysis. Thus, by shortening the extraction time and taking a small sample so as to reduce solvent removal time, the SB-ATR/FTIR procedure provides a very simple and rapid means of determining the FFA content of poultry feed lipids.
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Affiliation(s)
- S T H Sherazi
- National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro, Pakistan. tufail_sherazi@ yahoo.com
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Kumar A, Whitaker G, Kumar A. Electro-deposit polyaniline on carbon electrode for voltammetric detection of lipase. Biosens Bioelectron 2005; 21:513-7. [PMID: 16076442 DOI: 10.1016/j.bios.2004.10.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2004] [Revised: 10/22/2004] [Accepted: 10/27/2004] [Indexed: 11/18/2022]
Abstract
Normally, the pancreatic digestive enzymes are created and carried into the duodenum in an inactive form. During pancreatitis attacks, these enzymes are inhibited from reaching the duodenum, become activated while still in the pancreas, and begin to autodigest and destroy the pancreas. In order to accurately detect lipase within seconds, a square wave technique was explored without immobilizing enzyme and any other biomolecules over the electrode surface. The cyclic voltammetric (CV) technique was used to coat a carbon electrode with a thin layer of polyaniline. This modified electrode proved to be highly sensitive and specific to detect lipase between 0 and 225 IU/L, which is well within the normal physiological range. The consistency and reliability of this technique proved to be a very formidable detector of lipase present in abnormal quantities due to pancreatitis and other pathological disorders. The interference test has been performed to detect the lipase in the presence of amylase 50, 100, and 150 IU/L to understand the interference phenomenon with lipase detection. There is no significant effect of the amylase concentration over lipase detection resulting from using a modified carbon electrode. The response time of the modified carbon electrode is approximately 5s and the electrode has shown to be stable for 4 weeks at room temperature without special storage condition.
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Affiliation(s)
- Arun Kumar
- Nanomaterial and Nanomanufacturing Research Center and Department of Mechanical Engineering, University of South Florida, Tampa, FL, USA
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Kotani A, Miyaguchi Y, Tomita E, Takamura K, Kusu F. Determination of organic acids by high-performance liquid chromatography with electrochemical detection during wine brewing. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2004; 52:1440-1444. [PMID: 15030193 DOI: 10.1021/jf0306486] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Voltammetric determination of acids by means of the electrochemical reduction of quinone was applied to high-performance liquid chromatography (HPLC) with electrochemical detection (ED) for determining organic acids in fruit wines. A two-channel HPLC-ED system was fabricated by use of an ion-exclusion column and an electrochemical detector with a glassy carbon working electrode. Aqueous solution of 0.1 mM HClO(4) and ethanol containing 2-methyl-1,4-naphthoquinone served as a mobile phase and reagent solution, respectively. Determination of acetic, citric, lactic, malic, succinic, and tartaric acids was made by measuring the peak areas of the flow signals due to the reduction current of quinone caused by the eluted acids. The peak area was found to be linearly related to the acid amount ranging from 0.1 to 40 nmol per 20 microL injection. The present method was characterized by reproducibility with the simple and rapid procedure without derivatization of analytes. The method was shown as an effective means for following acid contents in fruit juices during fermentation with wine yeast.
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Affiliation(s)
- Akira Kotani
- Department of Analytical Chemistry, School of Pharmacy, Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
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Voltammetric determination of weak bases based on oxidation of α-tocopherol in an unbuffered solution. J Electroanal Chem (Lausanne) 2003. [DOI: 10.1016/s0022-0728(03)00351-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Li J, Peng T. Response to high acidity and basicity at a platinum electrode in chronopotentiometry. Anal Chim Acta 2003. [DOI: 10.1016/s0003-2670(02)01513-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Kotani A, Miyaguchi Y, Harada D, Kusu F. A Disposable Voltammetric Cell for Determining the Titratable Acidity in Vinegar. ANAL SCI 2003; 19:1473-6. [PMID: 14640441 DOI: 10.2116/analsci.19.1473] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A disposable voltammetric cell using three pencil leads as working, reference, and counter electrodes was developed for determining the titratable acidity, i.e. the acid content in vinegar. The materials of the pencil leads were graphite-reinforcement carbons (GRCs). A voltammetric determination of acid was made by measuring the reduction prepeak current of 3,5-di-t-butyl-1,2-benzoquinone (DBBQ) due to the presence of acids in unbuffered solution. The potential stability of the pseudo-reference electrode of GRC was examined. The prepeak current was found to be proportional to the acetic acid concentration from 0.05 to 2.7 mM with a correlation coefficient of 0.999. The cell-to-cell reproducibility for 1 mM acetic acid was evaluated with ten individual disposable cells. The RSD of the prepeak current and the SD of the prepeak potential were 2.56% and 0.008, respectively. The titratable acidity in five vinegar samples was determined by voltammetry using disposable cells and compared with that of the titratable acidity determined by the conventional potentiometric titration method. We then observed the results by both methods, and found a correlation coefficient of 0.972. As such, the voltammetry using disposable-cell required only one thousandth the volume of a vinegar sample for the titration method. The disposable cell was superior to the conventional electrochemical cell, in terms of facility, environment-friendly, and economy, and thus a sensor using the present cell would be useful for routine work in the quality control of vinegar.
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Affiliation(s)
- Akira Kotani
- School of Pharmacy, Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
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Kotani A, Kusu F, Takamura K. New electrochemical detection method in high-performance liquid chromatography for determining free fatty acids. Anal Chim Acta 2002. [DOI: 10.1016/s0003-2670(01)01520-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Casella IG, Gatta M. Determination of aliphatic organic acids by high-performance liquid chromatography with pulsed electrochemical detection. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2002; 50:23-28. [PMID: 11754537 DOI: 10.1021/jf010557d] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A new ion exclusion HPLC procedure accomplished with a pulsed electrochemical detection for the determination of several common aliphatic acids is described. A triple-step waveform of the applied potentials, based on the formation/inhibition of PtOH species on the electrode surface, is successfully used for sensitive detection of several aliphatic acids in flowing systems avoiding pre- or postcolumn derivatization and/or cleanup procedures. Under optimal chromatographic conditions (i.e., 50 mM HClO(4)) the proposed method allowed detection limits between 0.5 and 7 microM for all investigated acids, and the dynamic linear range spanned generally over 1 or 2 orders of magnitude. Determination of citric, malic, tartaric, lactic, formic, and acetic acids in several foods and beverages was performed, in approximately 15 min, without the necessity of any sample pretreatment.
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Affiliation(s)
- Innocenzo G Casella
- Dipartimento di Chimica, Università degli Studi della Basilicata, Via N. Sauro 85, 85100 Potenza, Italy
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MIYAGUCHI Y, KOTANI A, KUSU F. Determination of lactic acid in human plasma by HPLC with electrochemical detection. BUNSEKI KAGAKU 2002. [DOI: 10.2116/bunsekikagaku.51.703] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Yuji MIYAGUCHI
- School of Pharmacy, Tokyo University of Pharmacy and Life Science
| | - Akira KOTANI
- School of Pharmacy, Tokyo University of Pharmacy and Life Science
| | - Fumiyo KUSU
- School of Pharmacy, Tokyo University of Pharmacy and Life Science
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Nann T, Urban GA. Deposition of hydroquinone-thiosulfate on gold by means of anodic oxidation. J Electroanal Chem (Lausanne) 2001. [DOI: 10.1016/s0022-0728(01)00483-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Kim J, Chung T, Kim H. Determination of biologically active acids based on the electrochemical reduction of quinone in acetonitrile+water mixed solvent. J Electroanal Chem (Lausanne) 2001. [DOI: 10.1016/s0022-0728(00)00489-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Kim HS, Chung T, Kim H. Voltammetric determination of the pKa of various acids in polar aprotic solvents using 1,4-benzoquinone. J Electroanal Chem (Lausanne) 2001. [DOI: 10.1016/s0022-0728(00)00413-7] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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