Rapid Separation and Analysis of Six Organic Acids in Bayer Liquors by RP-HPLC after Solid-Phase Extraction

A rapid revised phase high-performance liquid chromatographic (RP-HPLC) method for the determination of six organic acids in Bayer liquors is reported. Oxalic, tartaric, acetic, succinic, glutaric and butene dicarboxylic acid were separated and quantified in 10 min. First time repeatability, reproducibility and recoveries were determined out for these acids in Bayer liquors. The organic acids were removed from Bayer liquor by using a solid-phase extraction procedure with anion-exchange cartridges. The chromatographic separation was achieved with only one Kromasil RP-C18 column thermo stated at 25 degrees C. Organic acids were detected with a UV-vis detector (215 nm). The precision results showed that the relative standard deviations of the repeatability and reproducibility were < 2.80% and < 3.74%, respectively. The accuracy of the method was confirmed with an average recovery ranging between 85.2 and 107.3%. Under optimum conditions the detection limits ranged from 50 to 1000 mg/L.

[Relationships between cadmium accumulation and organic acids in leaves of Solanum nigrum L. as a cadmium-hyperaccumulator]

The influence of different cadmium concentrations on the organic acid level in leaves of the Cd hyperaccumulator, Solanum nigrum L., in particular, the relationship of organic acids with Cd accumulation in S. nigrum was investigated based on the pot-culture experiment. The results showed that the Cd concentration in S. nigrum leaves exceeded 100 microg x g(-1), the threshold value used to define Cd-hyperaccumulators, and the bioaccumulation coefficient of cadmium in shoots of S. nigrum was higher than 1 when Cd concentration in soil was 25 microg x g(-1). The level of organic acids in leaves of S. nigrum had significant differences between the seedling stage and the mature stage. At the seedling stage, the sequence of organic acids in leaves of S. nigrum was acetic acid> tartaric acid> malic acid> citric acid. On the contrary, the accumulation of organic acids in S. nigrum at the mature stage was approximately in the following sequence malic acid> tartaric acid, acetic acid> citric acid. The significant positive correlation between Cd accumulation in leaves of S. nigrum and the concentration of tartaric acid in leaves of S. nigrum was observed at the seedling stage, whereas there was a significant positive correlation between Cd accumulation in leaves of S. nigrum and both acetic and citric acid concentrations at the mature stage. These results indicated that tartaric, acetic and citric acids in leaves of S. nigrum might act as the indication of Cd hyperaccumulation.

Application of electron spin resonance spectroscopy and spin probes to investigate the effect of ingredients on changes in wheat dough during heating

The change in microviscosity of the aqueous and lipid phases of wheat flour dough, during heating and subsequent cooling, has been measured using novel spin probes based on the isoindolin-yloxyl structure. The spin probes, water and/or lipid soluble, were used with combinations of dough ingredients: diacetyl tartaric acid ester of monoglycerides (DATEM), salt, yeast, and sodium ascorbate. The lipid soluble probe showed that DATEM does not produce a homogeneous phase with endogenous lipids but is found in a separate, less mobile phase. Also, the lipids were shown not to be involved in the baking process, although DATEM may be incorporated into the gelled starch matrix. The water soluble probe enabled starch gelatinization to be investigated in detail and showed that gelatinization produces a reduction of dielectric constant. The technique is appropriate for the detailed examination of the behavior of different ingredients during baking and also potentially to examine interactions between ingredients and flour components in dough.

Determination of α-hydroxy acids in cosmetic products by capillary electrophoresis

In this work, a simple and reliable method for the simultaneous analysis of alpha-hydroxy acids such as tartaric, glycolic and lactic acids in cosmetic products was developed using capillary electrophoresis with indirect UV detection at 254 nm. A buffer solution containing 10 mmoll(-1) potassium phthalate (pH 4.1) and 0.5 mmoll(-1) cetyltrimethylammonium bromide as electroosmotic flow modifier allowed baseline resolution of the analytes in approximately 3 min. A few validation parameters of the proposed method include: good linearity for all compounds in the range from 10 to 100 mgl(-1) with coefficients of correlation larger than 0.9999. The average recoveries of tartaric, glycolic and lactic acids in commercial samples were 99.12, 99.41 and 99.43%, respectively. The method presented acceptable precision with average relative standard deviation of 0.54% (assay of commercial samples), 0.44% (peak area) and 0.16% (migration time).

Determination of the enantiomeric excess of an M3 antagonist drug substance by chemometric analysis of the IR spectra of different guest-host complexes

A novel approach for the potential on-line determination of the enantiomeric excess (ee) of an M3 antagonist drug substance combining attenuated total reflectance infrared (ATR-IR) spectroscopy, guest-host complexes, and chemometric data analysis is described. Chiral recognition through a formation of diastereomeric complexes was measured by ATR-IR. Small changes on the IR spectra reflect the interaction between the guest (M3) and host (chiral selector). These changes are measured as a function of M3 enantiomer excess. The standard error of prediction is 1.3 ee%. The prediction results based on the IR method were in good agreement with the gravimetric method. The robustness of the calibration model was evaluated by varying the concentration of the chiral selector, the pH of the solution, and the organic solvents. The stability of the calibration model was also demonstrated through measuring different sets of samples on different days.

Pyrolysis mass spectrometry for distinguishing potential hoax materials from bioterror agents

Pyrolysis mass spectrometry (PyMS) was investigated as a rapid tool to distinguish potential bioterror hoax materials from samples containing pathogenic bacteria. A pyrolysis time-of-flight (TOF) mass spectrometer equipped with an alternative ionization technique, metastable atom bombardment (MAB), was used to produce sample spectra. These spectra were analyzed by principal component and discriminant analysis for pattern recognition. Materials investigated were two strains of Vibrio parahaemolyticus, one of which produced the tdh toxin, two Salmonella enterica serotypes, a biological mosquito control product containing spores of Bacillus thuringiensis, and several white to off-white powders (which could be used as hoax materials), such as flour, corn starch, methyl cellulose, and xanthan gum. PyMS distinguished bacterial samples from hoax materials. Furthermore, pattern analysis differentiated Vibrios from Salmonellae, Salmonella enterica Anatum from S. enterica Heidelberg, and the two V. parahaemolyticus strains from each other. The B. thuringiensis mixture was distinguished from other bacteria and powders, suggesting that PyMS with pattern recognition may differentiate samples containing pathogens, including Bacillus spp., from nonbiological agents and that it can be a rapid method for detection of bacteria. MS data acquisition took only 7 min for each sample.

A naked-eye sensing ensemble for the selective detection of citrate—but not tartrate or malate—in water based on a tris-cationic receptor

Citrate 3 can be selectively detected in aqueous solvents even in the presence of malate or tartrate using a naked-eye detection system based on the complex between tris-cation 1 and carboxyfluorescein 2.

Calcium tartrate crystals in the midgut of the grape leafhopper

Calcium tartrate crystals were observed in the midgut of grape leafhoppers. This unique compound was found for the first time in insects. The size of the crystals varied strongly between and within individuals with a mean length of 153 +/- 87 microm and a mean width of 71 +/- 46 microm. In addition, the number of crystals per individual showed a broad variation and ranged from 1 to 150 crystals/individual. The occurrence of calcium tartrate crystals as well as the number of crystals per individual followed the same seasonal pattern as seasonal vine leaf concentrations of tartaric acid found in a previous study, indicating that calcium tartrate is formed to neutralize the tartaric acid in the gut system. It further implies that the grape leafhopper, rather than being a pure phloem sucker, employs a mixed feeding strategy to satisfy its demands for calcium uptake.

Quantifying crystal form content in physical mixtures of (+/-)-tartaric acid and (+)-tartaric acid using near infrared reflectance spectroscopy

The objective of this study was to use diffuse reflectance near infrared spectroscopy (NIRS) to determine racemic compound content in physical mixtures composed primarily of the enantiomorph and to assess the error, instrument reproducibility and limits of detection (LOD) and quantification (LOQ) of the method. Physical mixtures ranging from 0 to 25% (+/-)-tartaric acid in (+)-tartaric acid were prepared and spectra of the powder samples contained in glass vials were obtained using a Foss NIRSystems Model 5000 monochrometer equipped with a Rapid Content Analyzer scanning from 1100 to 2500 nm. A calibration curve was constructed by plotting (+/-)-tartaric acid weight percent against the 2(nd) derivative values of log (1/R) vs lambda at a single wavelength, normalized with a denominator wavelength (1480 nm/1280 nm). Excellent linearity was observed (R(2)=0.9999). The standard error of calibration (SEC) was 0.07 and the standard error of prediction (SEP) for the validation set was 0.11. Instrument and method errors for samples in the 2% composition range ((+/-)-tartaric acid in (+)-tartaric acid) were less than 1% RSD and 3% RSD, respectively. The practical LOD and LOQ were 0.1% and 0.5%, respectively, and comparable to the calculated LOD and LOQ. These studies show that NIRS can be used as a rapid and sensitive quantitative method for determining racemate content in the presence of the enatiomerically pure crystal in the solid-state.

13C and 18O isotopic analysis to determine the origin of L-tartaric acid

Due to the ever-increasing amount of attention paid to the 'naturalness' of ingredients in food and beverages by both consumers and controlling authorities, the search for suitable methods for the characterisation of origin is of primary importance. Within the European Community the wine production industry is often faced with the problem of origin control of tartaric acid. This has led to the decision that only L-tartaric acid extracted from grapes (therefore natural) should be used. In order to implement these regulations, a screening of different techniques has been carried out to assess the methodology that best identifies the origin of the tartaric acid. It has already been indicated in previous scientific literature that isotope ratio mass spectrometry is an ideal technique for this type of identification. In this paper we present the results obtained for the measurement of the isotope ratios of carbon-13 and oxygen-18 of natural and synthetic samples of L-tartaric acid considering also natural samples of different geographical origin and years of production.

Multicomponent complex formation between vinpocetine, cyclodextrins, tartaric acid and water-soluble polymers monitored by NMR and solubility studies

This work deals with multicomponent complex formation of vinpocetine (VP) with beta-cyclodextrin (betaCD), sulfobutyl ether beta-cyclodextrin (SBEbetaCD) and tartaric acid (TA), in the presence or absence of water-soluble polymers, in aqueous solution. Complexation was monitored by phase-solubility and proton nuclear magnetic resonance ((1)H NMR) studies. TA demonstrated a synergistic effect on VP solubility, and in the complexation efficiency of betaCD and SBEbetaCD. Additionally, water-soluble polymers increased even more the complexation efficiency of the CDs that was reflected by a 2.1-2.5 increase on K(C) values for VP-CD-TA-polymer multicomponent complexes. SBEbetaCD was more effective in VP solubilization, as K(C) values of VP-SBEbetaCD-TA multicomponent complexes were notably higher than in corresponding betaCD complexes. The large chemical shift displacements from protons located in the interior of the hydrophobic CD cavities (i.e., H-3 and H-5) coupled with significant chemical shift displacements of VP aromatic protons suggested that this moiety was included in the cavity of both betaCD and SBEbetaCD. Two-dimensional rotating frame nuclear Overhauser effect spectroscopy (ROESY) experiments were carried out in order to obtain information about the multicomponent complex geometry in solution. Inspection of ROESY spectra allowed the establishment of spatial proximities between all aromatic protons of VP and the internal protons of the CDs, confirming that the aromatic moiety of VP is included in CD cavities being deeply inserted in SBEbetaCD multicomponent complexes, since additional interactions with the sulfobutyl side chains were evidenced.

Characterization and in vitro degradation of poly(2,3-(1,4-diethyl tartrate)-co-2,3-isopropyliden tartrate)

In the present study, a less known polyester based on tartaric acid was characterized with respect to its degradation mechanism. Poly(2,3-(1,4-diethyl tartrate)-co-2,3-isopropyliden tartrate) (PTA) differs from commonly used biodegradable polyesters, such as poly(lactides-co-glycolides) (PLGA) by the presence of additional cleavable bonds in the polymer side chains. This modification results in different polymer properties and influences polymer degradation. The hydrolytic degradation of PTA was studied in parallel to PLGA using disc-shape matrices, which were obtained by compression-molding. The discs were incubated in pH 7.4 phosphate buffer solution at 37 degrees C. The degraded samples were characterized for percentage mass loss, water absorption, decay of molecular weight and change in glass transition temperature. The results demonstrate that the degradation of PTA proceeds via bulk erosion similar to PLGA. However, the degradation of PTA implants is characterized by a rapid mass loss within a short period of time appearing after a definite lag phase without remarkable mass loss. This makes the polymer promising for pulsatile drug release systems.

Threshold Detection Using Indicator-Displacement Assays: An Application in the Analysis of Malate in Pinot Noir Grapes

The mathematics for modeling indicator-displacement assay isotherms is presented and contrasted to the classical host-guest binding isotherm. It is shown that the signal response can be tuned to occur closer to 1 equiv of guest relative to a standard binding algorithm. This delay in response leads to a better triggering protocol for threshold detection schemes. The determination of malate in Pinot Noir must was calculated using this new mathematical model, which demonstrates how a color change can be tuned to occur near a desired concentration of analyte.

Bacteria-host interactions of Salmonella Paratyphi B dT+ in poultry

In recent years, a dramatic increase in incidence of the dextro-rotatory tartrate-positive variant (dT+) of Salmonella enterica subspecies enterica serovar Paratyphi B has been observed in poultry and poultry products. In the present study the interactions of this bacterium with the host were studied in vivo and in vitro in an attempt to explain the preferential association of this serotype with poultry. The ability of this organism to invade and multiply in chicken intestinal epithelial cells and the intracellular behaviour in chicken macrophages was studied in vitro using chicken cell lines. In vivo challenge experiments in specific pathogen-free chickens were carried out to determine the level of colonization of caeca and internal organs early after experimental infection. An in vivo trial with commercial broiler chickens, using a seeder model, was performed to determine whether S. Paratyphi B dT+ could persist and spread in broilers until slaughter. S. Paratyphi B dT+ invaded and multiplied in the chicken epithelial cell line and survived in a chicken macrophage cell line. The strain used colonized caeca and internal organs of chickens to a high extent 1 week after infection with a low-dose inoculum. Moreover, the strain was efficiently transmitted within a group of broilers and persisted until slaughter. It was concluded that S. Paratyphi B dT+ was well adapted to poultry and therefore it is suggested that specific control measures against this serotype should be considered.

High-performance liquid chromatographic separation and quantification of citric, lactic, malic, oxalic and tartaric acids using a post-column photochemical reaction and chemiluminescence detection

An HPLC method was developed for the determination of citric, lactic, malic, oxalic and tartaric acids by chemiluminescent detection following online irradiation with visible light. The organic acids were irradiated with visible light in the presence of Fe3+ and UO2(2+) to generate Fe2+, which was determined by measuring the chemiluminescence intensity in a luminol system in the absence of added oxidant. Factors affecting the photochemical and chemiluminescence reactions were optimised so that their contribution to the total band-broadening was negligible. The chromatographic separation was performed on a C18 column under isocratic reversed-phase conditions using 0.005 M H2SO4 mobile phase. The optimised method was validated with respect to linearity, precision, limits of detection and quantification, accuracy specificity and robustness. The applicability of the assay was demonstrated by analysing these compounds in real samples such as milk, fruit juices, soft drinks, wine and beer.

Evaluation of chiral recognition characteristics of metal and proton complexes of di-o-benzoyl-tartaric acid dibutyl ester and L-tryptophan in the gas phase

Chiral recognition of di-o-benzoyl-tartaric acid dibutyl ester (T) was achieved in the gas phase by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry. In this method two divalent transition metal cations, zinc(II) and copper(II), were used as binding metal ions, and L-tryptophan (A) was used as a chiral reference. Multimeric complexes were readily formed by electrospray ionization of a methanol:water (50:50) solution containing metal ion, L-tryptophan and T. These multimeric complexes included singly charged protonated dimeric [TAH](+), doubly charged copper(II) bound tetrameric [TACu-H](2)(2+) and doubly charged zinc(II) bound tetrameric [TAZn-H](2)(2+), together with other complexes. The mass-selected complex, i.e., [TAH](+), [TACu-H](2)(2+) and [TAZn-H](2)(2+), was used to acquire the second stage mass spectra. The chiral recognition capability of these three complexes was evaluated using the abundance ratios of daughter ion to parent ion. A high degree of chiral recognition ability was observed in [TACu-H](2)(2+) and [TAZn-H](2)(2+). It was found that the type of binding ion played an important role in the chiral recognition. Different binding ions exhibited distinctive dissociation pathways and unique chiral recognition characteristics. The present method is based not only on whole-molecule loss but also on fractional-molecule loss. In addition, the reproducibility of the chiral recognition method was confirmed by several determinations of the abundance ratios of daughter ion to parent ion with a fixed activation energy and with five different activation energies. It was also shown that this chiral recognition method can tolerate acid interference.

Histochemical analysis of phenylphenalenone-related compounds in Xiphidium caeruleum (Haemodoraceae)

Phenylphenalenones represent a typical group of secondary metabolites of the Haemodoraceae. Some of these phenolic compounds show organ-specific distribution within the plant. However, detailed information on cellular localisation is still lacking. To this end, confocal laser-scanning microscopy, microspectral photometry and high-performance liquid chromatography were used to study the tissue localisation of phenylphenalenone-type compounds in Xiphidium caeruleum Aubl. From the autofluorescence potential of these compounds, specific distribution of allophanylglucosides and non-glucosidic compounds of the phenylphenalenone-type in distinct cells of the roots (apical meristem, cortex, cap, epidermis) and the shoot system was revealed. Fluorescence enhancement using "Naturstoff reagent A" (NA) indicated the occurrence of NA-positive natural products in the vacuoles of leaf epidermal cells. The present results provide new insights into the possible functions of phenylphenalenone-related compounds in the context of their localisation. Additionally, the advantages and limitations of the techniques are discussed.

Protective agents used to reverse the metabolic changes induced in wine yeasts by concomitant osmotic and thermal stress

AIMS

The reversion of the metabolic changes induced in wine yeasts by stressors.

METHODS

Six strains of Saccharomyces were inoculated in grape must containing over 400 g l-1 of sugar and incubated at 35 degrees C, both with and without the addition of 100 mg l-1 of catechin, inositol or SO2.

RESULTS

Significant correlations between addition of the stress-protectants and change in the metabolic behaviour of the wine yeasts were observed. Depending on strain and protectant, and expressing data as a percentage of increase or decrease compared to the control, fermentation vigour after 3 d increased by up to 10%, titratable acidity of the wines increased by up to 7%, ethanol content increased by up to 20%, unitary acetic acid production decreased by up to 35%, and unitary glycerol production decreased by up to 20%. IMPACT OF STUDY: By using protective agents it is possible to minimize the abnormal fermentation performance that wine yeasts exhibit under thermal and osmotic stress.

Phytochemical variation in echinacea from roots and flowerheads of wild and cultivated populations

Quantitative phytochemical variation was determined from roots and inflorescences of native plant populations in the genus Echinacea. Specimens were collected in situ throughout the natural range of each putative taxon and transplanted to greenhouse cultivation. Ethanolic extracts from individual plants were separated by reversed-phase HPLC to quantify the alkamides, polyenes/ynes, and phenolics, and then grouped by age and taxonomically, according to a recent morphometric taxonomic revision of the genus. Canonical discriminant analysis revealed that cichoric acid, the diene alkamides 1-3 and 7, and ketoalkene 24 were the best taxonomic markers. Mean content for each of 26 phytochemicals revealed useful agronomic information, such as those varieties and organs with the highest accumulations, as well as the optimal age and growth conditions for each variety. The highest amounts of cichoric acid were measured from the older, wild inflorescences of E. pallida var.sanguinea, whereas the highest quantities of the alkamides 1-3 and 7 were present in roots of wild and transplanted E. purpurea. Baseline phytochemical data and chromatographic profiles for all types of wild Echinacea may be used for protection of wild stands, germplasm identification, and crop improvement.

Simultaneous and direct determination of oxalic acid, tartaric acid, malic acid, vitamin C, citric acid, and succinic acid in Fructus mume by reversed-phase high-performance liquid chromatography

A method for the simultaneous separation and direct determination of oxalic acid (OA), tartaric acid (TA), malic acid (MA), vitamin C (VC), citric acid (CA), and succinic acid (SA) in Fructus mume using reversed-phase high-performance liquid chromatography with a UV detector in an acidic medium is presented in this study. In the experiment, the optimization of chromatographic conditions (i.e., the pH and flow rate of the mobile phase, the absorption wavelength, and temperature of column) that affect the separation degree and peak shape of organic acids has been obtained. The linear ranges are found to be 0.05-4.7 microg for OA (r = 0.9999), 0.11-10.5 microg for TA (r = 0.9999), 0.114-11.4 microg for MA (r = 0.9999), 0.033-3.30 microg for VC (r = 0.9999), 0.155-15.5 microg for CA (r = 0.9998), and 0.194-19.4 microg for SA (r = 0.9996). For OA, TA, MA, VC, CA, and SA, the even recovery (n = 3) of six effective components are 100.9%, 99.97%, 101.2%, 102.1%, 101.1%, and 100.7%, respectively, and the largest relative standard deviation (n = 11) for the six components is less than 1.7%. The detection limits are 0.01 microg for OA, TA, and VC; 0.05 microg for MA; 0.03 microg for CA; and 0.1 microg for SA. In a single chromatographic run, OA, TA, MA, VC, CA, and SA can be determined in less than 7 min. The method can be used for the purpose of routine analysis and the quality control of a botanic (Fructus mume) containing these effective components.

Teaching old indicators new tricks

Most synthetic sensors are designed with covalent attachment between a receptor and a reporter moiety. In this report, we describe the current progress of our use of noncovalently attached indicators to signal binding of analytes. With these systems, analyte binding leads to indicator displacement from the binding cavity, which in turn yields an optical signal modulation. We include previous examples, the strategies involved in our development, and the advantages as well as disadvantages of this method. Finally, our latest research in this field is briefly presented.

Direct chiral resolution of tartaric acid in food products by ligand exchange capillary electrophoresis using copper(II)-D-quinic acid as a chiral selector

Chiral resolution of native DL-tartaric acid was performed by ligand-exchange capillary electrophoresis using copper(II)-D-quinic acid as a chiral selector. Factors affecting chiral resolution, migration time, and peak area of tartaric acid were studied. The running conditions for optimum separation of tartaric acid were found to be 1 mM copper(II) sulfate-10 mM D-quinic acid (pH 5.0) with an effective voltage of -15 kV at 30 degrees C, using direct detection at 250 nm, and resolution of racemic tartaric acid was approximately 1.3. With this system, chiral resolution of DL-tartaric acid in food products was conducted successfully.

[Simultaneous determination of 11 organic acids in fruit juice by ion exclusion chromatography]

A method for the quantitative determination of 11 organic acids (oxalic acid, citric acid, tartaric acid, malic acid, ascorbic acid, lactic acid, succinic acid, formic acid, acetic acid, glutaric acid and fumaric acid) in fruit juice was developed successfully. It was based on an ion exclusion chromatographic separation under the conditions of isocratic elution with 17 mmol/L sulphuric acid solution with the ICE-ION-300 ion exclusion column, and the UV detection at 210 nm. The precision of the method was investigated and the relative standard deviations were from 1.5% to 9.8% (n = 10).

[Measurement of binding constants of metal complex by indirect ultraviolet affinity capillary electrophoresis]

The binding constants of complexes formed by metal ions and ligands have been obtained by affinity capillary electrophoresis, according to the measurement of the migration times of metal ions effected by ligands in aqueous media, under the experimental model named electrophoretic peak shifting. This method has been applied to the research of magnesium ion with citric acid and manganese ion with tartaric acid. Under the condition of imidazole and acetate buffer (pH 5.01) at 20 kV running voltage, the migration times of metal ion with ligand of different concentrations have been measured. The estimated logarithmic values of binding constants after computation were 3.27 for magnesium-citric acid and 2.28 for manganese-tartaric acid, which showed that the results were in agreement with the data in previous literature. This method is applicable to the measurement of the binding constants of complex systems with 1:1 ratio.

Determination of tartaric acid in wines by FIA with tubular tartrate-selective electrodes

A flow injection analysis (FIA) system comprising a tartrate-(TAT) selective electrode has been developed for determination of tartaric acid in wines. Several electrodes constructed for this purpose had a PVC membrane with a complex of quaternary ammonium and TAT as anion exchanger, a phenol derivative as additive, and a more or less polar mediator solvent. Characterization of the electrodes showed behavior was best for membranes with o-nitrophenyl octyl ether as solvent. On injection of 500 microL into a phosphate buffer carrier (pH = 3.1; ionic strength 10(-2) mol/L) flowing at 3 mL/min, the slope was 58.06 +/- 0.6 with a lower limit of linear range of 5.0 x 10(-4) mol/L TAT and R2 = 0.9989. The interference of several species, e.g. chloride, bromide, iodide, nitrate, gallic acid, tannin, sucrose, glucose, fructose, acetate, and citrate, was evaluated in terms of potentiometric selectivity coefficients. The Hofmeister series was followed for inorganic species and the most interfering organic ion was citrate. When red and white wines were analyzed and the results compared with those from an independent method they were found to be accurate, with relative standard deviations below 5.0%.