Eluent tartaric acid

Simultaneous determination of both cations and anions in acid rain has been achieved using a portable conductimetric ion-exclusion cation-exchange chromatographic analyzer.14 This system utilized the poly(meth-ylmethacrylate)-based weak acid cation exchange resin TSK-Gel OA-PAK-A, (Tosoh , Tokyo, Japan) with an eluent of tartaric acid-methanol-water. All of the desired species, 3 anions and 5 cations, were separated in less than 30 minutes detection limits were on the order of 10 ppb. Simultaneous determination of nitrate, phosphate, and ammonium ions in wastewater has been reported utilizing isocratic IEC followed by sequential flow injection analysis.9 The ammonium cations were detected by colorimetry, while the anions were measured by conductivity. These determinations could be done with a single injection and the run time was under 9 minutes. 

Kwon, S.-M., Lee, K.-P., Tanaka, K., and Ohta, K., Simultaneous determination of anions and cations by ion-exclusion chromatography-cation-exchange chromatography with tartaric acid/18-crown-6 as eluent, /. Chromatogr. A, 850, 79, 1999. 

Figure 4.7 Anion exchange separation of carboxylic acids in red wine. Column, Shodex C811, 100 cm x 7.6 mm i.d. eluent, 3 mM perchloric acid flow rate, 0.9 ml min-1 temperature, 60 °C detection, reaction detection using chloro-phenol red at 430 nm. Peaks 1, citric acid 2, tartaric acid 3, malic acid 4, succinic acid 5, lactic acid 6, formic acid and 1, acetic acid.

For white wines (85), a similar HPLC condition to that of Betes-Saura et al. (79) was employed with a Nucleosil C)8 column (250 X 4.0-mm ID, 5 /zm) with binary gradient using eluent (A) acidified water (pH 2.65) and eluent (B) 20% A with 80% acetonitrile applied for hydroxy-cinnamate derivatives esters (caffeoyl tartaric, p-coumaroyl tartaric, and feruloyl tartaric acid esters) and free hydroxycinnamic acids (caffeic, ferulic, and p-coumaric acids). 

Figure 9. Analysis of anions and cations in river water using tartaric acid/18-crown-6/methanol-water eluent with a carboxylated polyacylate stationary phase in the protonated form. Ions 1) sulfate 2) chloride 3) nitrate 4) eluent dip 5) unknown 6) sodium 7) ammonium 8) potassium 9) magnesium 10) calcium (from ref. 80)...

Fig. 3. HPLC chromatograms of cell liquid in Mackaya cordata root. Column NOVA-pack C g (5p.), 8 mm x 10 cm eluent 0.1 iV tartaric acid (containing 0.125% sodium dodecyl sulfate)— acetonitrile, 45 55 at 2.0 ml/min detection UV, 285 nm. (a) Alkaloid (colored) cell, (b) Colorless cell. Peaks a, protopine b, allocryptopine c, sanguinarine d, chelerythrine.

Figure 4 shows the typical concentration results for a 10-ppm solution of cadmium, magnesium, and zinc. The injected sample solution contained 50 pg of each in 5 mL of 0.1 M tartaric acid solution, adjusted to pH to 9.25. The mobile phase was pumped at a flow rate of 0.05 mL/min. Rotational speed was 950 rpm. The eluent was collected every 2 min (0.1-mL fractions). The fractions were diluted 1 10 with water, and the emission intensity for each element was measured by plasma atomic emission spectrometer. The emission intensities for each element were increased 20-fold compared with the original sample solution. The results of this study demonstrated the high-performance capabilities of the pH-zone refining technique. Trace elements in the sample solution could be successfully concentrated into a small volume, almost under 0.1 mL with an enormous level of enrichment. 

The chromatogram shown in Fig. 3-29 exemplifies how strongly the selectivity of a separation system depends on the eluent. A silica ion exchanger, TSK GEL IC-SW from Toyo Soda Company was employed as the stationary phase. The separation of chlorate and nitrate that is achieved using tartaric acid at a concentration of 0.001 mol/L... 

Fig. 3-29. Separation of various inorganic anions on a TSK Gel IC-SW silica-based anion exchanger. - Eluent 0.001 mol/L tartaric acid (pH 3.2) flow rate 1.5 mol/L detection direct conductivity injection volume 100 pL solute concentrations 10 ppm each.

Fig. 3-86. Comparison between the retention behavior of inorganic anions and several organic carboxylic acids, respectively. - Separator column IonPac AS4 eluent 0.0028 mol/L NaHC03 + 0.0022 mol/L Na2C03 flow rate 1.6 mL/min detection suppressed conductivity injection 50 pL solute concentrations a) 1.5 ppm fluoride (1), 2 ppm chloride (2), 5 ppm orthophosphate (3) and bromide (4), 10 ppm nitrate (5), and 12.5 ppm sulfate (6), b) 5 ppm formic acid (7), 40 ppm benzoic acid (8), 20 ppm succinic acid (9), 10 ppm malonic acid (10), 20 ppm maleic acid (11), tartaric acid (12), and oxalic acid (13).

Polymethacrylate and polyvinyl resins play only a secondary role in the manufacture of cation exchangers. Presently, the only polymethacrylate-based cation exchanger is offered by Sykam (Gauting, Germany) under the trade name LCA K02. This column differs from its PS/DVB analogue (see Table 3-24) only in the particle size (5 pm) and exchange capacity (0.4 mequiv/g). With a tartaric acid eluent, this phase is preferred for the analysis of heavy and transition metals. 

Fig. 3-135. Separation of alkali and alkaline-earth metals on Super-Sep. — Eluent 0.005 mol/L tartaric acid flow rate 1 mL/min detection direct conductivity injection volume 10 pL solute concentrations 1 ppm lithium, 5 ppm sodium, and ammonium, 10 ppm each of potassium, magnesium, and calcium, 20 ppm strontium and barium.

Fig. 3-143. Separation of alkaline-earth metals at Shimpack IC-C1. -Eluent 0.004 mol/L tartaric acid + 0.002 mol/L ethylenediamine flow rate 1.5 mL/min detection direct conductivity injection volume 20 pL solute concentrations 5 ppm magnesium, 10 ppm calcium, 20 ppm strontium, and 36 ppm barium.

The simultaneous analysis of the most important alkali and alkaline-earth metals was once impossible due to their markedly different retention behavior. However, the inorganic chemists have finally realized their dream this analytical problem no longer poses a problem. One of the two possible solutions is the novel silica-based cation exchanger modified with poly(butadiene-maleic acid), introduced in Section 3.4.I.3. As shown in Fig. 3-135, the most important alkali and alkaline-earth metals and ammonium can be analyzed in a single run via direct conductivity detection using tartaric acid as the eluent. The extremely short time required for such a separation is quite impressive. 

Fig. 3-149. Separation of divalent cations with direct conductivity detection. - Separator column surface-sulfonated cation exchanger (Benson Co., Reno, USA) eluent 0.0015 mol/L ethylenediamine + 0.002 mol/L tartaric acid, pH 4.0 flow rate 0.85 mL/min injection volume 100 pL solute concentrations 10.3 ppm Zn2+, 9.1 ppm Co2+, 16 ppm Mn2+, 16.1 ppm Cd2+, 17.1 ppm Ca2+, 16 ppm Pb2+, and 20.3 ppm Sr2+ (taken from [148]).

Fig. 3-153. Separation of heavy and transition metals on a polymethacrylate-based cation exchanger. - Separator column Sykam LCA A02 eluent 0.1 mol/L tartaric acid, pH 2.95 with NaOH flow rate 2 mL/min detection photometry at 500 nm after reaction with PAR and ZnEDTA injection volume 100 pL solute concentrations 2 ppm Fe3+ and Cu2+, 4 ppm Pb2+, 1 ppm Zn2+, 2 ppm Ni2+ and Co2+, 4 ppm Cd2+, 1.8 ppm Fe2+, 1 ppm Ca2+ and Mg2+.

A significantly better separation between iron(III), copper, and nickel is accomplished on a polymethacrylate-based cation exchanger using pure tartaric acid as the eluent. As the respective chromatogram in Fig. 3-153 reveals, iron(III) still elutes near the void volume, which renders the quantitation of this signal more difficult. The addition of ZnEDTA to the PAR reagent is very advantageous, because it enables the simultaneous detection of alkaline-earth metals. 

Fig. 4-2. Separation of organic acids on PRP-X300. - Eluent 0.0005 mol/L H2S04 flow rate 1 mL/min detection direct conductivity injection volume 100 pL solute concentrations 4 ppm tartaric acid, 7.5 ppm malic acid and citric acid, 10 ppm lactic acid, 25 ppm acetic acid, and 40 ppm succinic acid.

Fig. 4-8. Separation of organic acids upon application of a membrane-based suppressor system. — Separator column IonPac ICE-AS1 eluent 0.001 mol/L octanesulfonic acid flow rate 1 mL/min detection suppressed conductivity injection volume 50 pL solute concentrations 50 ppm oxalic acid (1), 50 ppm tartaric acid (2), 25 ppm fluoride (3), 50 ppm lactic acid (4), 50 ppm formic acid (5), 50 ppm acetic acid (6), and 100 ppm propionic acid (7).

A separation of the ions in acid rain is shown in Fig. 8.7 using conductivity detection. The peaks of the anions (sulfate, chloride and nitrate), which are highly ionized, are positive. The cation peaks are of lower conductivity than the tartaric acid eluent and hence are in the negative direction. The detection limits are low enough to handle most acid rain samples without any preconcentration (Table 8.4). 

Figwe 8.9. Wine analysis by high re.solution ion exclusion. Analysis Conditions Column Transgenomic ION-300 Eluent 0.005 N H2SO4 Flow rate 0.3 mL/min Temperature 60 °C Detection DrI Sample 1. citric acid. 2. tartaric acid, 3. glucose. 4. malic acid, 5. fructo.se.6. acetic acid. 7. glycerol, 8. methanol. 9. ethanol. 

A 1-g portion of the modified catalyst was washed with THF (two 10 cm portions), methanol (two 10 cm portions), and distilled water (two 10 cm portions). The catalyst was suspended in 15 cm of a 1 mol dm NaOH solution at 373 K to remove the tartaric acid from the surface to the solution. The supernatant was collected by decantation, and the remaining catalyst was washed three times with lOcm water. After the combination of the supernatant and the washings, the solution was filled to 50 cm with water. The amormt of tartaric acid was determined by an ion chromatograph equipped with a Shodex KC-811 (8 mm ID X 300 mm) at 313 K. The eluent 1 mmol dm perchloric acid. 

Among many ligands used for simultaneous ion chromatography of metals, the most common eluents used are oxalic acid, tartaric acid, citric acid, 4-(2-pirydylazo)resorcinol (PAR), pyridine-2,6-dicarboxylic acid (PDCA), a-hydroxyi-sobutyric acid (HIBA), 1,2-diaminocyclohexanetetraacetic acid (DCTA), diethylenetriarninepentaacetic acid (DTPA), and ethylenediaminetetraacetic acid (EDTA). 

RG. 5. Separation of transition metals by ion interaction chromatography. A Waters (xBondapak C g column was used with SO mM tartaric acid and 2 mM sodium octanesulfonate at pH 3.4 as eluent. Detection by postcolumn reaction with PAR. The detection wavelength was S46 nm. Solute concentrations Co (S ppm) Ni, Cd (2 ppm) remainder (1 ppm). (Courtesy of Waters Chromatography Division.)... 

The modification of silica gel with various metals is a simple and effective way to prepare ion exchangers that often have unique selectivities for analyte ions. Ohta et al. [49] described the preparation of a cation exchanger in which silica gel was first immersed in zirconium butoxide, Zr (OC4H9)4. Then the material was calcined (heated) at temperatures up to 1000 °C to form a sihca-zirconia product An excellent separation of all the alkaU metal ions plus ammonium was obtained with 10 mM tartaric acid as the eluent. Divalent metal cations were strongly retained. 

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