A Disposable Voltammetric Cell for Determining the Titratable Acidity in Vinegar

Kotani, Akio; Miyaguchi, Yuji; Harada, Dai; Kusu, Fumiyo

doi:10.2116/analsci.19.1473

Cited by 16 publications

(15 citation statements)

References 10 publications

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“…25 The prepeak height was found to be proportional to the acetic acid concentration from 0.05 to 2.7 mM (r = 0.999) and propionic, butyric, and lactic acids concentrations from 0.05 to 2.5 mM (r >0.999). 29 Based on these findings, acid in the eluate from the separation column in the HPLC system was detected by measuring the current height of a flow signal at the fixed potential. The choice of VK3 as a quinone reagent for preparing the quinone solution was favorable, as it facilitated this determination owing to its reduction potential, stability and solubility in ethanol.…”

Section: Determination Of Scfas By Hplc-ecdmentioning

confidence: 99%

“…We previously developed a new method for determining acids by voltammetry using a quinone reagent. 25 Since the method was shown to be quite sensitive and selective for acids, the method was successfully applied to the determination of the free fatty acid (FFA) content of fats and oils, 26-28 the total acid content of vinegar, 29 and the FFA concentrations of plasma. In the present study, an HPLC system with electrochemical detection (HPLC-ECD) was fabricated for determining SCFAs in rat and human feces.…”

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confidence: 99%

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Determination of Short-chain Fatty Acids in Rat and Human Feces by High-Performance Liquid Chromatography with Electrochemical Detection

et al. 2009

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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 HClO4 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. IntroductionThe bacteria in human colon obtain energy for growth by fermenting carbohydrates in the colonic lumen, mainly polysaccharides of plant cell walls (dietary "fiber") and some starch. The end-products include around 200 to 400 mmol day -1 of short-chain fatty acids (SCFAs) such as acetic, propionic, and butyric acids. Over 90% are absorbed and used by host, contributing 2 to 10% of daily energy requirements. 1,2 This is particularly important in premature babies with lactose malabsorption. 3 An extensive disease of the bowel, surgical bypass, prolonged antibiotic therapy, total parenteral nutrition, malabsorption, immaturity 4,5 and wide variation in dietary fiber intake may all disturb this important host/bacterial symbiosis. 1,2Since fecal SCFAs reflect colonic fermentation, 6 they are measured in studies to investigate and manipulate such disturbances. Moreover, fecal SCFA composition ratio of ulcerative colitis patients remarkably changes in comparison with that for a healthy human. In particular, the composition of lactic acid, called non-volatile fatty acid (NVFA), increased in comparison with that of acetic, propionic, and butyric acids, called volatile fatty acid (VFA), in feces of ulcerative colitis patients. [7][8][9][10][11][12] Thus, the determination of fecal SCFAs is significant to examine homeostasis, characteristics, and metabolism of intestinal bacterial flora, and it would be useful for monitoring of and diagnostic strategy against diseases in the colon.The determination of SCFAs has been carried out by gas chromatography (GC) [13][14][15][16][17][18] and high-performance liquid chromatography with ultraviolet detection (HPLC-UV), fluorescent detection (HPLC-FL), or mass spectrometric detection (LC-MS). [19][20][21][22][23][24] The fecal analysis by GC required the complicate cleanup of the sample, and it was hard to detect NVFAs ...

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Section: Determination Of Scfas By Hplc-ecdmentioning

confidence: 99%

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confidence: 99%

Determination of Short-chain Fatty Acids in Rat and Human Feces by High-Performance Liquid Chromatography with Electrochemical Detection

et al. 2009

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“…Although their potential is unknown and depends on the solution composition, they do provide a constant potential value. The simplicity, facile design and processability of such type of electrodes have made them attractive in electrochemical systems used in the monitoring of corrosion and redox processes at high temperatures, 33 impedance spectroscopy measurements, 34,35 biosensors, 36,37 screenprinted electrodes, 38,39 and potentiometric, 40 and voltammetric 41 determinations. For in vivo measurements, pseudo-reference electrodes are used in substitution to the conventional saturated calomel (SCE) and Ag/AgCl reference electrodes.…”

Section: Validation Of the Pseudo-reference Electrodementioning

confidence: 99%

In vivo human electrochemical properties of a NiTi‐based alloy (Nitinol) used for minimally invasive implants

Pértile

Silva

Peccin

et al. 2008

J Biomedical Materials Res

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The development of a homemade device for in vivo human determination of the open circuit potential (OCP) of Nitinol is described. Pseudo-reference electrodes (316L stainless steel and Pt) were initially tested and validated in vitro using simulated body fluids. As judged from the excellent electrochemical responses in terms of both accuracy and precision, the most ideal system comprised the combination of sterilized Pt (pseudo-reference) and Nitinol (working) needle-shaped electrodes. The average in vivo human OCP determined from independent measurements on six human patients with indication of direct arterial surgery was -0.334 +/- 0.030 V/SCE. This value was in good agreement with data recorded in vitro using simulated body fluids (-0.313 +/- 0.003 V/SCE in AFNOR S90-701 artificial saliva; -0.334 +/- 0.001 V/SCE in artificial urine; -0.239 +/- 0.007 V/SCE in Ringer's solution). The thin surface film protecting the bulk NiTi alloy is therefore not susceptible to active dissolution at rest as long as the break down potentials (>>0.0 V/SCE) so far reported are well above OCP measured in this study. These results highlight the importance of evaluating the corrosion resistance of Nitinol under realistic conditions (mechanical loads, wear and fatigue) in order to establish multifaceted mechanisms that might lead to accelerated dissolution and failure of implanted stents.

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“…The literature describes many applications of GRC electrodes: for determining the titratable acidity in vinegar [3,4]; in abrasive stripping voltammetry [5]; in determination of ozone [6], dopamine [7], caffeine [8], trepibutone [9], uric acid [10]; in simultaneous determination of nitrite, dopamine and serotonin [11]; as substrate for mercury [12] and bismuth [13] films in trace metal determination; in liquid chromatography for determination of phenols [14]; applied with modified surface for determination of 2,4-dichlorophenol [15]; in voltammetry of microparticles [16]; in studies of copper-chelating properties of flavonoids [17]; in studies of DNA hybridization [18][19][20][21]; for discrimination of herpes type [22]; in detection of hepatitis B virus DNA [23,24] and in studies of interaction between DNA and lycorine [25], arsenic trioxide [26] and cis-DDP [27] molecules.…”

Section: Introductionmentioning

confidence: 99%

Influence of pencil lead hardness on voltammetric response of graphite reinforcement carbon electrodes

Tavares

Barbeira

2008

J Appl Electrochem

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This work studied the voltammetric response of graphite reinforcement electrodes made of different pencil lead hardness. The studies showed that harder graphite leads, regardless of their manufacturer, are more appropriate as electrode material for voltammetric purposes due to their higher peak currents, increasing sensitivity and reproducibility, with DEp closer to the theoretical value for a reversible system.

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A Disposable Voltammetric Cell for Determining the Titratable Acidity in Vinegar

Cited by 16 publications

References 10 publications

Determination of Short-chain Fatty Acids in Rat and Human Feces by High-Performance Liquid Chromatography with Electrochemical Detection

Determination of Short-chain Fatty Acids in Rat and Human Feces by High-Performance Liquid Chromatography with Electrochemical Detection

In vivo human electrochemical properties of a NiTi‐based alloy (Nitinol) used for minimally invasive implants

Influence of pencil lead hardness on voltammetric response of graphite reinforcement carbon electrodes

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