Anion Exchange Resin Column Research Articles

Sulfur isotope ratio (34S:32S) measurements in plant material by inductively coupled plasma mass spectrometry

The34S : 32S isotope ratio in plant material was determined using measurements at m/z 48 and 50, corresponding to the 32S16O+ and 34S16O+ species, respectively, by inductively coupled plasma mass spectrometry (ICP-MS). The sulfur species in aqueous solutions and plant digests were separated and pre-concentrated in an anion-exchange resin (AG1-X8) column inserted in a flow system. The isotope ratio measurements for a sulfur solution containing 17 mg l–1 was characterized by an RSD of <1%. Results for plant material enriched in 34S were in agreement with those obtained by magnetic deflection mass spectrometry using electron ionization at the 95% confidence level. A sample throughput of 45 h–1 was achieved.

Precise measurement of zirconium isotopes by thermal ionization mass spectrometry

An analytical method for high-precision measurement of zirconium isotope ratios using a Sector thermal ionization mass spectrometer (TIMS) its reported. The chemical separation procedure of Zr has been refined by employing a small anion exchange resin column to minimize the Mo interference on 92Zr, 94Zr and 96Zr. To confirm the reproducibility of this technique, Zr isotope analyses from six commercially available chemical samples and from two meteorites were carried out. Isotopic ratios were corrected for mass fractionation by normalization with the 94Zr 90Zr ratio. The determined ratios 91 90 , 92 90 and 96 90 were within the precision range 0.002 to 0.007% (relative standard deviations). The data indicate the existence of zirconium isotopic heterogeneity in the earth and the possibility of pre-terrestrially printed and terrestrially conserved isotope aberration patterns of zirconium is discussed.

Quantification of 1,5-anhydro- d-glucitol in urine by automated borate complex anion-exchange chromatography with an immobilized enzyme reactor

HPLC using a borate form of a strongly anion-exchange resin column and an immobilized enzyme reactor for colorimetric detection was used to quantify urinary 1,5-anhydro- d-glucitol. Urine samples were introduced into the system every 7 min without any pretreatment, and after separation of interfering substances in the column, 1,5-anhydro- d-glucitol was successively detected. Quantitative determination of urinary 1,5-anhydro- d-glucitol was possible within the 1.2–300 μmol/l range. The coefficient of variance was less than 3% and the correlation between results obtained with our system ( y) and those obtained by gas chromatography–mass spectrometry ( x) was y=0.983 x−1.287 μmol/l ( n=42, r=0.998).

Removal of radioiodine from liquid effluents

Various methods have been evaluated for the removal of 131I from actual liquid waste received from a reactor and from simulated effluents containing the isotope. The options included both precipitation (along with silver iodide and bismuth hydroxide) and ion-exchange/adsorption (using anionic exchangers and activated carbon) processes. Of all the schemes, passing through anion exchange resin columns was found to be the most effective, indicating that iodine was present mostly as anions.

Flow-Injection Chemiluminescence Sensor for the Determination of Free Chlorine in Tap Water

ABSTRACT A novel chemiluminescence(CL) sensor combined with flow-injection analysis has been developed for determining free chlorine in tap water. The analytical reagent luminol was immobilized on an anion exchange resin column. While a volumn of sodium hydroxide passed through the column, luminol was eluted from the resin in alkaline aqueous solution and then mixed with a sample stream to react and produce CL. The CL emission intensity was correlated with the standard ClO− concentration in the range 1×10−8 to 4×10−5 g ml−1, and the detection limit was 8×10−9 g ml−1 ClO−. Interfering metal ions present in water were effectively separated by a pre-column cation exchanger. A complete analysis, including sampling and washing, could be performed in 1 min with a relative standard deviation of less than 5%. The sensor was stable for over 200 times and has been applied successfully to the determination of ClO− in tap water.

Chemiluminescence flow system for vanadium(v) with immobilized reagents.

A chemiluminescence (CL)-based system for vanadium(v) combined with flow-injection analysis is described. The analytical regents, luminol and hexacyanoferrate(II), were both immobilized on an anion-exchange resin column. When a volume of phosphoric acid was passed through the column, these two reagents were eluted from the resin and then mixed with a vanadium(v) stream under acidic conditions. By means of the fast oxidation reaction between vanadium(v) and hexacyanoferrate(II), vanadium(IV) and hexacyanoferrate (III) were generated, both of which catalyzed the oxidation of luminol by dissolved oxygen in aqueous alkaline solution to produce CL. The CL emission intensity was correlated with the standard vanadium (v) concentration in the range from 1.0 x 10(-2) to 10 micrograms cm-3, and the detection limit was 5.4 x 10(-3) micrograms cm-3 vanadium (v). Interfering metal ions co-existing in sample solutions could be effectively separated on-line by a cation-exchange column placed upstream. A complete analysis, including sampling and washing, could be performed in 1 min with a relative standard deviation of less than 5%. The system was stable for over 100 analyses and was applied successfully to the determination of vanadium in geochemical and human hair samples.

Oligosaccharide Release from Frozen and Paraffin-Wax-Embedded Archival Tissues

Altered glycosylation is a feature of many solid tissue diseases such as ulcerative colitis, Crohn's disease, cancer, and connective tissue disorders. Conventionally, oligosaccharide changes have been studied by immunohistochemical techniques. We have adapted existing techniques, developed for purified protein preparations, to allow the release of intact oligosaccharides from archival tissues, so that the oligosaccharides may be structurally characterized. In our study, sections cut from paraffin-wax blocks were dewaxed and oligosaccharides were released using hydrazine and labeled with 2-aminobenzamide. Sialylated oligosaccharides were compared by passing through a GlycoSep C divinylbenzene anion exchange resin column and neutral oligosaccharides were compared by passing through a BioGel P4 column. The oligosaccharide profiles obtained from the same fresh frozen versus archival paraffin-wax-embedded, normal liver, and tumor tissues showed remarkable similarity in terms of their sialylated and neutral structures. Matrix-assisted laser desorption ionization mass spectrometry has shown that the oligosaccharides are not affected by fixation in formalin and storage in paraffin wax. The results indicate that while the proteins themselves may be denatured, oligosaccharides are not adversely affected by fixation in formalin and storage in paraffin wax. By applying these methods, oligosaccharides from archival tissues, where the natural history of the disease has been followed, may now be liberated and structurally characterized.

Cell Recycle and Broth Reuse Fermentation with Cross-Flow Filtration and Ion-Exchange Resin

A novel integrated fermentation system in which cross-flow filtration was coupled to an anion-exchange resin column was developed to achieve biomass recycle and broth reuse for lactic acid fermentation. An anion-exchange resin column was employed to recover lactic acid from the spent broth. The effluent was diluted with fresh medium, supplemented with glucose and nutrients. Spent broth was reused for three consecutive biomass recycle fermentations with no significant decrease in fermentation performance. The fermentation system enabled simultaneously high productivity of lactic acid (average value 7.75 g dm -3 h -1 and total amount of lactic acid produced 85.21 g dm -3 after 11 h fermentation), high productivity of cells (average value 2.00 g dm -3 h -1 ) and efficient utilization of medium (about 75% of the spent broth was reutilized). The system described may be applied to other organic fermentations subject to end-product inhibition.

A separation method to overcome the interference of calcium on the uranium determination by ICP-ES.

The accurate determination of uranium by Inductively Coupled Plasma Emission Spectrometry (ICP-ES) in calcium phosphate matrix suffers from a severe ionization interference due to the high calcium content of the samples. This leads to a signal depression up to 30%. For reliable determinations an extraction method based on anion exchange resin column chromatography is described which separates uranium for the needs in ICP-ES measurements. The results are comparable with results obtained by other determination methods. In addition, reference materials were measured to verify this extraction procedure.

Facile analysis of ribonucleotides in d,l-α-difluoromethylornithine-treated mouse lymphoid cells by high-performance anion-exchange column chromatography

Using high-performance liquid chromatography with the strong anion-exchange resin column CDR-10 for analysis of ribonucleotides, the effects of d,l-α-difluoromethylornithine (DFMO) on ribonucleotides of mouse leukemic lymphoid cells SC-1 have been studied. More than 16 nucleoside mono-, di and triphosphates, and unknown peaks were clearly separated and measured without increase in baseline rise using the gradient systems of phosphate buffer. The ATP level in DFMO-treated SC-1 cells was reduced, but was reversed by exogenous putrescine. These facts may suggest that polyamine depletion by DFMO during a short time (6 h) caused mitochondrial damage in mammalian cells.

Anion-exchange preparation of a 232U radiotracer for α-particle liquid scintillation counting

Daughter product ingrowths, which could act as analytical interferences, are removed from 232U(VI) stock solutions prior to use as an α-particle emitting radiotracer in conjunction with detection by liquid scintillation counting. The preparative benchtop separation procedure employs elution with HCl through a BioRad AG1-X8 anion-exchange resin column, and fraction collection. The importance of the separation of the 232U isotope from daughter products, characterized by high recovery, is illustrated by liquid scintillation energy spectra. Rapid ingrowth in the purified fraction also limits the period of time after purification in which the radiotracer is usable.

Chemiluminescence flow sensor for the determination of ascorbic acid with immobilized reagents

A novel flow sensor based on chemiluminescence (CL) for the determination of ascorbic acid has been proposed. The analytical reagents, luminol and ferricyanide, were both immobilized on an anion-exchange resin column. The CL signal produced by the reaction between luminol and ferricyanide, which were eluted from the column through sodium phosphate injection, was decreased in the presence of ascorbic acid. The CL emission intensity was linear with ascorbic acid concentration in the range 0.01–0.8 μg ml −1; the detection limit was 5.5 × 10 −3 μg ml −1. The whole process, including sampling and washing, could be completed in 1 min with a relative standard deviation of less than 5%. The sensor could be reused more than 100 times and has been applied successfully to the analysis of ascorbic acid in pills and vegetables.

Chemiluminescence flow system for the monitoring of chromium(VI) in water

A novel chemiluminescence(CL) system has been developed for determining chromium(VI) in water. The analytical reagents involved in the CL reaction, including luminol and hexacyanoferrate(II) were both immobilized on an anion exchange resin column. While a volume of sodium phosphate was passed through the column, these two reagents were eluted from the resins and then mixed with a chromium(VI) stream containing hydrochloric acid. By the fast oxidation reaction between chromium(VI) and hexacyanoferrate(II), hexacyanoferrate(III) was generated, which then reacted with luminol in alkaline aqueous solution to produce CL. The CL emission intensity was correlated with the chromium(VI) concentration in the range 4 × 10 −8 to 1 × 10 −6 g ml −1, and the detection limit was 1.4 × 10 −8 g ml −1 chromium(VI). Interfering metal ions present in water were effectively separated by a pre-column cation exchanger. A complete analysis, including sampling and washing, could be performed in 1 min with a relative standard deviation of less than 5%. The system was stable for over 200 analyses and has been applied successfully to the determination of chromium(VT) in water samples.

Synthesis and Characterization of Highly Pure Form of Sodium Salt of Anionic, Thiomalatogold(I) Complex with Antiarthritic Activity. Analogs of Anionic, Thiomalatosilver(I) Complex with Antimicrobial Activity

Abstract Sodium salt of anionic Au(I) complex with a trianion of thiomalic acid tma3− (H3tma = HOOCCH(SH)CH2COOH), known as an effective antiarthritic drug, was prepared in highly pure form by one-step synthesis from NaAuCl4 and tma3− in aqueous solution. The reaction consisted of a reduction of Au(III) by tma3− and the following complexation of Au(I) with tma3− ligand. The disulfide species of tma3− formed by this reduction was removed by passing through an anion-exchange resin column and the contaminating NaCl by passing through a gel filtration column. The tma–Au(I) complex was also prepared by another reaction based on ligand exchange of the intermediate complex AuCl(thiodiglycol) with tma3−. It was purified using the anion-exchange resin and gel filtration columns. The target compound, finally isolated in 30% yield in highly pure form, has been characterized by complete elemental analyses, TG/DTA, FT-IR, 1H and 13C NMR spectroscopies, and molecular weight was determined in aqueous solution by molmass measurement based on the cryoscopic method combined with dissociation degree determination based on the [Na+] measurement in equilibrium state using a Na+-ion selective electrode. This Au(I) complex was an oligomer with a formula of {Na2[Au(tma)]·1.75H2O}n (n = 3—10; MW = 1260—4220). This polymerization degree, low in comparison with previously proposed data, was determined in the neutral aqueous solution without any other electrolytes under the concentration range CNa = 0.914—182.9 mmol dm−3. The tma–Au(I) complex exists in an oligomeric form both in the solid and in aqueous solution. The properties of the oligomeric tma–Au(I) complex were compared with those of the previously reported complex and a commercially available sample, and also with those of the recently prepared, oligomeric tma–Ag(I) complex with antimicrobial activity.

Determination of low-level99Tc in environmental samples by high resolution ICP-MS

An analytical method has been developed for the determination of low-level99Tc in environmental samples by High Resolution ICP-MS. The method consists of leaching of99Tc by HNO3 and separation by three different solvent extractions with 30% TOA-xylene, MEK, and cyclohexanone. Finally, purification of99Tc was made by using an anion exchange resin column to reduce dissolved solids content. The final solution was adjusted to 1M HNO3 for introducing into the HR-ICP-MS. The accuracy and precision of the method was confirmed to be satisfactory by applying this technique to the determination of99Tc in IAEA marine algae sample (AG-B-1). Measurements of99Tc using 0.5–2.5 g of sediment samples from the Irish Sea, UK, were successfully performed by the present method.

Breakthrough volumes of TcO 4 − on Reillex™-HPQ anion exchange resin in a Hanford Double Shell Tank simulant

Abstract The breakthrough volumes on Reillex-HPQ anion exchange resin columns for TcO 4 – solutions have been determined. The feed solutions were a Handford Double Shell Tank Slurry (DSS) simulant of ionic strength () of 6.22 M and a TcO 4 – of 5.00×10–5 M and a 13 dilution of the DSS simulant, =2.07 M, with a TcO 4 – of 1.67×10–5 M. The DSS flow rates {mL simulant/(cross section area of column.min)} through the column varied from 0.19 to 20.5 cm/min. The 1% breakthrough volumes varied from 50.0 to 1.3 bed volumes (BV), respectively. The 13 DSS flow rate varied from 0.95 to 11.0 cm/min and had 1% breakthrough volumes ranging from 94 to 20 BV, respectively. At a flow rate of 1.0 cm/min, the breakthrough bed volumes are 10.2 and 95.8 BV for the DSS and 13 DSS solutions, respectively. Obviously, there is an advantage in processing the 13 dilution of the feed stream.

An ion-exchange method for selective separation of palladium, platinum and rhodium from solutions obtained by leaching automotive catalytic converters

An ion-exchange method has been developed for the separation of palladium, platinum and rhodium from a solution that is highly acidic and contains a considerable amount of lead, aluminum, iron and cerium, obtained by leaching a used honeycomb type automotive catalytic converter. A column of Amberlite IRA-93 anion-exchange resin was found appropriate to recover platinum metals from the pregnant solution. Selective stripping of these metals from the resin was achieved by eluting rhodium first with 6.0 M hydrochloric acid, then palladium with a 1% ammonia solution at ambient temperature, and platinum with 5% of the reagent at elevated temperatures. Optimum conditions for leaching these metals from the catalyst were 5.0 M hydrochloric acid and 0.4 M sodium chlorate at 70°C. This method can be applied to both analytical as well as large scale operations. It is simple, economical, and relatively safe for human exposure and the environment.

On-line ion exchange for the removal of sulfur anion interference on the determination of manganese in geothermal fluids by flow injection electrothermal atomic absorption spectrometry

An efficient flow injection system with an on-line anion-exchange resin column (Dowex-1) incorporated into a timebased injector is described for the removal of sulfur anion spectral interference for the determination of manganese by electrothermal atomic absorption spectrometry. The positive interference effect caused by high concentrations of sulfur ions could not be reduced by using different matrix modifiers. However, the elimination of this effect was possible by retaining the interferent species on the resin column and eluting the analyte with dilute nitric acid. The analyte plug was introduced into the graphite tube atomizer with a sampling arm assembly by means of positive displacement with air through a time-based solenoid valve. The entire system was controlled by a computer, independent of the spectrometer. This approach to the elimination of sulfur anion interference has been applied to geothermal fluids with a high content of these species. The linear range was from 0 to 15 µg l–1 and the detection limit was 0.2 µg l–1(4 pg) of manganese. The results were precise (2.8–3.2% RSD) and were in good agreement with those obtained by atomic absorption chelation–extraction, differences between mean values were <7%.

An Anion Adsorbent of the Anti-Hofmeister Type Based on Cobalt(III)-Loaded Chelating Resins Containing 1,4,8,1 l-Tetraazacyclotetradecane-5,7-dione

An anion adsorbent was developed based on a Cobalt(III)-loaded chelating resin containing 1, 4, 8, 11-tetraazacyclo-tetradecane-5, 7-dione. Batchwise adsorption study has revealed that the adsorbent exhibits an anti-Hofmeister anion selectivity sequence (OH->SCN->NO2-) and that it takes up thiocyanate preferentially in the presence of excess perchlorate as well. Column-mode study has also clarified that the adsorbent takes up thiocyanate preferentially even in the presence of tenfold excess perchlorate. The adsorbed thiocyanate is rapidly and quantitatively eluted with 0.2M sodium hydroxide, unlike to the case of a conventional anion exchange resin (Bio-Rad AG 1-X4) column. In addition, the adsorbent was able to be regenerated with hydrochloric acid solution for repeated use. During repeated use of the adsorbent for a half year, no loss of the loaded cobalt(III) was observed.

Liquid Chromatographic Analysis of Niacin in Fortified Food Products

An ion exchange liquid chromatographic (LC) method using an anion exchange resin column was developed for the determination of niacin in fortified foods. Samples were extracted by autoclaving with H2SO4 (1 + 1). Florisil open column chromatography was used to remove interferences from the sample extracts. Niacin levels were quantitated by an LC system using a 250 x 4.1 mm Hamilton PRP-X100 column, a mobile phase of 2% glacial acetic acid in water, and UV detection at 254 nm. The limit of detection was 0.11 micrograms niacin/mL, and the standard curve was linear from 0.24 to 0.80 micrograms niacin/mL. The system reproducibility was evaluated by completing 10 repetitive analyses on an infant formula and a macaroni product, which gave an average CV of 2.7%. Mean recovery (+/- standard deviation) was 99.8 +/- 7.7 (n = 15). The results compared favorably with those by the AOAC microbiological method.