Ion Exchange Resin Column Research Articles

Contamination of water and organic solvents stored in plastic bottles with phthalate ester plasticizers

Migration of phthalic acid esters into water, n-hexane, and methanol kept in polyethy-lene bottles or PVC tubes was investigated by high-performance liquid chromatography with a variable wavelength u.v. detector. The content of esters in water kept in contact with PVC for one day was 0.44 ppm and the migration rate of dibutyl phthalate was 4.8 × 10 -5 mg h -1 cm -2 of PVC tube. n-Hexane stored in a polyethylene bottle for 7 days contained 6 ppm esters; the migration rate of dibutyl phthalate was 6.4 × 10 -5 mg h -1 cm -2 of polyethylene. PVC tubing connected to ion-exchange resin columns contaminates deionized water with the esters.

Chromatographic and colorimetric detection of glycosylated hemoglobins: A comparative analysis of two different methods

The measurement of glycosylated hemoglobins in diabetic patients represents a new approach to the problem of the long-term glycemie control. Chromatographic procedures are usually employed to separate the glycosylated components of hemoglobin; we performed a comparative analysis of two different methods: Chromatographic and colorimetric. Chromatographic separation on small ion-exchange resin columns gives high precision (coefficient of variation = 1.7%) over the whole range of normal and diabetic values of percentage of glycosylated hemoglobin (3.2–15.9%). An alternative technique is the measurement of 5-hydroxymethylfurfural released by oxalic acid hydrolysis of the hexoses bound to hemoglobin, as proposed by Fluckiger and Winterhalter (Fluckiger, R. and Winterhalter, K.H. (1976) FEES Lett. 71, 356–360). Normal values, expressed as 5-hydroxymethylfurfural absorbance per 10 g of total hemoglobin, range from 133 to 235, with mean ± S.D. = 189 ± 26; while diabetic patients show a range from 220 to 443 and mean ± S.D. = 318 ± 65. This last method gives satisfactory precision over the entire range of values examined (coefficient of variation = 4.2%) and has proved simple and inexpensive. The correlation between the two methods is very high ( n = 20; r = 0.98; p < 0.001) with a regression line, y = 25. Ix + 40.3. The storage of the hemolysates at −20°C for up to 70 days for the colorimetric method and up to 260 for the Chromatographic procedure does not decrease the precision of either technique.

Preparation of cellodextrins: An engineering approach

The combination of Sephadex G-15 and ion-exchange resin columns allows one-step desalting and separation of cellodextrins using water as the sole eluent. The column apparatus described in this paper has the potential of producing up to 3 g cellodextrins in one day. In addition, the columns described are stable and do not require repacking or regeneration after each run. Hence the potential exists for scaling up this system for even greater production of cellodextrins if need be.

Dissimilatory nitrate reduction by liquid membrane encapsulated cell-free extracts and whole cells of Micrococcus denitrificans.

The combination of Sephadex G-15 and ion-exchange resin columns allows one-step desalting and separation of cellodextrins using water as the sole eluent. The column apparatus described in this paper has the potential of producing up to 3 g cellodextrins in one day. In addition, the columns described are stable and do not require repacking or regeneration after each run. Hence the potential exists for scaling up this system for even greater production of cellodextrins if need be.

A fixation‐decalcification procedure for bone biopsies

A procedure for the simultaneous fixation and decalcification of bone biopsies is described. Mild acidic fixatives (such as Bouin's fluid) are effective decalcifying agents when made calcium-free by a continuous circulation through a column of anion-binding ion exchange resin. The procedure has been found relatively fast, safe, economic and to provide excellent histology of biopsies containing cancellous bone.

Structural subunits of chondroitin sulfate isomers isolated from different aged human kidneys

Acidic glycosaminoglycans (AGAG) were extracted from whole human kidney tissues of different aged subjects and were purified by precipitation with cetylpyridinium chloride and by an ion exchange resin column chromatography. The prepared AGAG were individually digested with chondroitinase-AC and they were further digested with chondroitinase-ABC. The resulting unsaturated disaccharides and the undigested AGAG were identified by paper chromatography, electrophoresis, and other chemical analyses. The AGAG, which were resistant to chondroitinase-AC, were mainly heparan sulfates and their proportion to total AGAG appeared to decrease with the advance of age. Dermatan sulfate plus oversulfated dermatan sulfate were composed of one-fifth to one-third of the AGAG resistant to chondroitinase-AC, and their proportion tended to increase with the advance of age.

Removal of radioactive iodine from waste by using ion exchange resin column (author's transl)

Removal of radioactive iodine from waste by using ion exchange resin column (author's transl)

Endogenous activating factor for guanylate cyclase in synaptosomal-soluble fraction of rat brain.

When the crude mitochondrial fraction of rat brain was homogenized with distilled water and centrifuged, most of guanylate cyclase activity was detected in the soluble fraction. The total guanylate cyclase activity recovered in the soluble fraction was 5- to 8-fold higher than that of the crude mitochondrial fraction. The greater recovery of guanylate cyclase activity was found to be due to a release of an endogenous activating factor for guanylate cyclase. The activating factor was partially purified by acid extraction followed by a gel filtration and ion exchange resin columns. The factor was a dialyzable small molecule. The molecular weight was estimated to be between 300 and 600 by a Sephadex G-15 column and Diaflo ultrafilter membranes. It was stable in dilute acids, but labile in alkaline solution. It was readily soluble in water, but insoluble in organic solvents. Treatment with various enzymes, so far as tested, failed to abolish the activity. The activating factor stimulated the initial velocity of the reaction. It altered neither the Km value for GTP nor the dependency of the enzyme on divalent metals. The activation by the factor was due to an increase in the Vmax of the reaction. The activation was prevented by lysolecithin, Lubrol PX, hydroxylamine, methylhydroxylamine, or hemoglobin.

Occurrence of saxitoxin in a green turban shell.

From the viscera of a green turban shell Turbo marmorata collected at an Okinawan coral reef, a water soluble toxin resembling saxitoxin was obtained. The chromatographic behavior of the toxin on columns of ion exchange resin, silicic acid, and Sephadex LH-20 coincided well with that of saxitoxin. Thin-layer chromatography with two solvents also could not differentiate between the two toxins. In qualitative chemical tests, the green turban toxin was positive to Jaffe and Weber reagents, as was saxitoxin. As regards the biological activity, the two toxins gave practically the same dose-death time curves when tested on mice. From all these results it was concluded that the green turban toxin is identical with saxitoxin. This may be the first report of the occurrence of saxitoxin in a mollusk associated with coral reefs.

Identification of .DELTA.-valerobetaine and other betaines in the ovary of a shellfish Callista brevishiphonata.

Quaternary amines in the ovary of the shellfish Callista brevishiphonata were isolated by treatment on columns of ion-exchange resins and then by preparative paper chromatography. The presence of at least ten quaternary amines was recognized. Eight of these were identified by comparison with synthetic compounds by mass spectral analysis and by paper chromatography: Choline, glycine betaine, γ-butyrobetaine, δ-valerobetaine, stachydrine, valine betaine, homarine, and homoserine betaine.

A study of acidic glycosaminoglycans in human gastric tissue.

The acidic glycosaminoglycans (AGAG) in normal portions of human gastric tissue were separated by electrophoresis in 3 buffer systems. Paper chromatographic separation of the constitutional disaccharide units by digestion of chondroitin sulfates (CS) with chondroitinase-ABC and chondroitinase-AC was carried out after fractionation of CS by ion-exchange resin column chromatography. Thin-layer chromatography of hexosamines and other biochemical analysis were also performed. The presence of hyaluronic acid in the gastric tissue was substantiated by the enzymatic susceptibility to streptomyces hyaluronidase. The results indicated that human gastric AGAG consisted of, in the order of amount, heparan sulfates, dermatan sulfate, hyaluronic acid, chondroitin-4-sulfate, chondroitin-6-sulfate and presumably oversulfated chondroitin sulfate.

Demineralization by electrodialysis

Electrodialysis process using ion-exchange resins in the compartments has been an approach in demineralization of low saline solutions but the difficulty of maintaining and operating such systems is a major bottleneck. The current work has made use of the concept of conducting spacers of anion and cation-exchange type made from polyblends or interpolymers of polyethylene-styrene-divinylbenzene and placing them in juxtaposition with the respective membranes in the cell. The performance of a laboratory size electrodialysis unit using conducting and non-conducting spacers in two configurations and occupying 12.5 and 255 of cell volume and having 11 cell pairs with cross-sectional area of 66 cm 2 in desalting sodium chloride solutions of different concentration ranging from about 1000 ppm to 250 ppm down to 50 ppm or less has been reported. The output of the electrodialysis unit is raised by 2 to 3 times by using conducting spacers instead of the conventional non-conducting Spacers. It has been concluded that this approach offers a practical solution to bridge the gap between the conventional electro-dialysis desalination level of 500-1000 ppm and complete deionization using a scavenging mixed-bed ion-exchange column. The process is continuous and offers an economic alternative to conventional deionization by ion-exchange resin columns and can find application in concentration and recovery of valuable salts from dilute waste streams. This approach in demineralization also dispenses with the regenerant waste disposal problem encountered in ion-exchange resin demineralization plants.

Preparation of Polyvinylamine by the Hofmann Degradation of Polyacrylamide

Abstract Polyvinylamine which contained 95.6 mol% amine units was obtained when the Hofmann degradation was applied to polyacrylamide by use of a very slight excess of sodium hypochlorite and a large excess of sodium hydroxide at 0 to −15 °C for about 15 h. Polyvinylamine hydrochloride (PVAm·HCl) was isolated almost quantitatively as a white powder. PVAm·HCl was freely soluble in water, but insoluble in organic solvents such as methanol, acetone, dioxane, N,N-dimethylformamide (DMF), and dimethyl sulfoxide (DMSO). The desalting of PVAm·HCl was performed by passing its aqueous solution through columns of ion exchange resins. The product containing 30.5% nitrogen was obtained in reasonable yield. Polyvinylamine was freely soluble in water, acetic acid, or lower alcohols, but insoluble in solvents such as acetone, dioxane, DMF, and DMSO.

An improved isolation procedure for the gas chromatographic analysis of urinary polyamines.

The isolation of polyamines from urinary hydrolysates in a sufficiently pure state for subsequent analysis by gas chromatography has proved to be difficult. However, by using columns of Porapak-Q and ion-exchange resins, urinary hydrolysates are readily purified and formation of trifluoroacetyl derivatives of polyamines proceeds in high yield without carryover of artifacts in the gas chromatographic elution profile. Good yields from the trifluoroacetylation reaction are not achieved if large quantities of salts or urinary pigments are present. By obtaining the polyamine carbonates in the final stages of the method described, the trifluoroacetylation reaction yields excellent derivatives of nanogram or microgram amounts, particularly after standing over-night at room temperature. The procedure described in detail should permit routine urinary polyamine analysis where rapidity, ease of handling many samples, freedom from complications and artifacts are a consideration.

Studies on the chemical structure of tobacco hemicellulose. I. Xylan isolated from the stalk of Nicotiana tabacum.

Xylan was isolated by alkaline extraction of the holocellulose from the stalk of Nicotiana tabacum, which was purified by DEAE-cellulose and ion-exchange resin column chromatography. Based on the results of methylation analysis, partial acid hydrolysis and enzymatic hydrolysis, the purified xylan was confirmed to be composed of a straight chain of β-(1-4)-linked D-xylopyranosyl residues. The degree of polymerization was determined as about 100 by membrane osmometry in water.

Separation of homovanillic acid and vanillylmandelic acid with ion-exchange resin column.

Zugefugte exogene Homovanillinsaure und Vanillylmandelsaure im Extrakt aus Rattenhirn konnen durch Saulenchromatographie (Dowex-1-X2) abgetrennt werden. Die erstere wurde zu 85%, die letztere zu 98% wiedergewonnen.

Rapid Diagnosis of Sickle Cell Disease at Birth by Microcolumn Chromatography

Accurate specific diagnosis of sickle cell disease can now be made at birth on routinely obtained cord blood samples by microcolumn chromatography. The method uses a small column of a cation ion exchange resin, CM-Sephadex, and a single developer that allows definitive rapid distinction of hemoglobin SS, AS, AC, SC, and CC, within two hours. Seventy-five samples or more per day have been analyzed by one technician in a laboratory without special precautions or equipment. In a program which has been initiated on a large, totally unpredictable obstetrical service in Los Angeles, 10,401 consecutively born infants have been studied for hemoglobin type without regard to racial origin. Three SS infants, 1 SC, 143 AS infants, and 37 AC infants as well as several with other abnormal hemoglobins have been identified without interfering with the routine operation of the delivery rooms of the obstetrical service. The diagnosis of sickle cell disease has been confirmed on subsequent examinations of the infants. The feasibility of using microcolumn chromatography as a rapid, accurate, inexpensive, and easy method for the rapid diagnosis of sickle cell disease in newborns has now been established.

Analysis of urinary mucopolysaccharides using small ion exchange columns

Methods are presented for the small scale column chromatography of urinary mucopolysaccharides. After isolation by cety pyridinium chloride mucopolysaccharides are applied to a small column of ion exchange resin and eluted by 2 M-sodium chloride. Colorimetric assays on this elutate allow clinically significant disease states to be detected.

21] Phosphorylated 3-deoxy-2-ketaldonic acids

This chapter discusses the phosphorylated 3-deoxy-2-ketaldonic acids. The α -hydroxy group of a phosphorylated 3-deoxyaldonic acid is selectively oxidized by chlorate in the presence of vanadium oxide and phosphoric acid, and the keto acid is isolated by ion exchange chromatography. For the preparation of 3- deoxy-D-erythro-hex-2-ulosonic acid 6-phosphate, to a mixture of glucometasaccharinic acid 6-phosphate, 3 lithium salt (930 mg), commercial vanadium oxide (V 2 O 5 , 9 mg), and potassium chlorate (129 mg), 3 ml of water containing 0.105 ml of phosphoric acid (85%, d , 1.71) is added. The mixture is well shaken, and is passed through a column (100 ml) of Amberlite IR-120 (or Dowex 50) ion exchange resin in the H + form, and the pH of the acidic effluent is brought to 7.5 by addition of 1 N ammonium hydroxide solution. For the preparation of 3-deoxy-D-arabino-hept-2-ulosonic acid 7-phosphate, 2-Deoxy D-arabino- hexose 6-phosphate 6 (“2-deoxy D-glucose 6-phosphate”), 1.2 g, Li salt, are dissolved in water (5 ml) and KCN (780 mg) is added. The mixture is kept in a closed vessel in the cold room for 48 hr and then decationized by passing through a column (100 ml) of Amberlite IR-120 ion exchange resin in the H + form. For the preparation of 3-deoxy D-arabino- hept - 2-ulosonate 7-phosphate, the Ba salt (530 mg) is suspended in water (10 ml), and sufficient Amberlite IR-120 H + resin is added to bind all the Ba ions. The mixture is well stirred, and the resin is filtered off and thoroughly washed with water. 2-deoxyglucose 6-phosphate can be obtained from the relatively inexpensive 2-deoxyglucose by preparing its α -methyl pyranoside, which is transformed into the 6-phosphate.

Ability of an ion-exchange resin to retain 137Cs in the presence of Ca2+ ions at fast flow rates.

The absorption of 137Cs dissolved in water that contained Ca2+ ions was investigated for water flowing through a Na+ - form ion-exchange resin column at flow rates between 0.3 and 1.2 l./min/cm2. The absorption was found to be an exponential function depending on the length of the resin and an absorption coefficient. The absorption coefficient depends on the flow rate of the water and the concentration of Ca2+ ions in the water. The results indicate that more than 90% of the 137Cs in a fresh water sample can be quickly concentrated at the sampling site using an ion exchange column approximately 40 cm in length.