Eluents potassium chloride

Figure 4.21 Monitoring of an enzyme reaction using size-exclusion liquid chromatography. Column, TSK GEL G3000SW, 60 cm x 7.5 mm i.d. eluent, 0.07 M potassium phosphate buffer containing 0.1 M potassium chloride flow rate, 1 ml min-1 detection, UV 280 nm. Peaks 1, fl-lactoglobulin 2, a-chymotrypsin, and 3, decomposed products.

The decomposition products were separated by eluting with potassium chloride solution on a column packed with anion-exchange resin, Dowex 1x4 in chloride form. During the elution the concentration of potassium chloride in the eluent was increased exponentially. The phosphorus contents in effluent fractions were determined colorimetrically with a molybdenum(V)-molybdenum(VI) reagent (4J. 

The second direct method depends on the ability of aqueous potassium chloride, adjusted to pH 4 with carbon dioxide, to selectively elute hydrogen ions from sulfonic acid groups in pulps that first have been converted to their hydrogen form with 0.1 M hydrochloric acid (Cappelen and Schoon 1966). Carbon dioxide is removed from the eluent by sparging with nitrogen and the remaining acid is titrated with 0.1 M sodium hydroxide. Again, a correction factor for interference from carboxylic acids is required. This factor, as before, is based on the protons eluted from bleached pulps by the eluent. As the results depend on the concentration of potassium chloride used, the letter is adjusted so that the sulfonate content corresponds to the sulfur content of pulps assumed to contain only acidic sulfur. 

The position of the carousel is controlled automatically and only three positions are actively used. In the first position the eluent is deposited on the potassium chloride, in the second position a stream of air is drawn through the potassium chloride to remove the solvent and in the third position the spectrum is taken. The use of the carousel containing potassium chloride powder certainly increased the sensitivity of the LC/IR combination, but the finite intervals of sample collection made the system unsuitable for modern high efficiency columns. Jino and Fujimoto [30,31] employed a potassium bromide plate as a transport system. The eluent from a small bore column (flow rate 5 pi/ min)... 

Conroy and Griffiths [34] developed a solvent extraction device that could be employed with a LC/FTIR combination. The device involved an extraction procedure that took the column eluent and continuously extracted the dissolved solute into dichloromethane. The dichloromethane was then concentrated and finally dispersed onto a plug of potassium chloride powder. This device appears a little clumsy and, fact, is really and offfline fraction collecting procedure. 

Phenolic aldehydes and ketones have been chromatographed on silica gel G and cellulose plates as their phenylhydrazones formed in situ. Toluene-chloroform-acetone (5 3 2), chloroform-acetone (8 2), anisole-methanol (8 2), and anisole-chloroform-acetone (5 3 2) are the eluents used for silica gel, whereas the layers of cellulose have been eluted with 2% formic acid, 20% potassium chloride, 10% acetic acid, or isopropanol-ammonia-water (8 1 1). 

Under the prerequisite that the cell constant and the equivalent ionic conductances of eluent anions and eluent cations are known, Eq. (181) makes it possible to calculate the conductivity of typical eluents for this kind of detection method. To determine the cell constant, the conductance of a potassium chloride solution with defined concentration is usually measured, as the equivalent ionic conductances of potassium and chloride ions are known with 74 S cm2 vaf1 and 76 S cm2 val-1, respectively (see Table 6-1). 

Tjaden et used a home made coulometric detector (GCE, -1-0.9 V vs Ag/ AgCl) to measure perphenazine and fluphenazine (Figure 6.35). A methyl-modified silica column was used with methanol-aq. phosphate (50 mmol L , pH 6.9) (53-1-47) containing potassium chloride (7gL ) as eluent. Subsequently, cyanopropyl-modified silica columns were used with GCEs and acetonitrile-aq. phosphate buflfer or ammonium acetate solution as eluents, although Murakami et employed an ODS-modified column with acetonitrile-THF-pyridine-aq. acetate buffer (0.1 molL , pH 3.5) (69-1-1-1- 0.1 -1- 30) as eluent in the assay of chlorpromazine (Figure 6.35) and levomepromazine. Similarly both... 

The insecticide carbaryl (1-naphthyl-A-methylcarbamate, Figure 7.4) has been measured on filter paper exposed during aerial spraying using an ODS-modified silica column and ED (GCE, +0.75 V vs Ag/AgCl) after pre-column alkaline hydrolysis to 1-naphthol. The eluent was acetonitrile-acetic acid-aq. potassium chloride (0.5 mol L ) (50 + 1 + 49). 2-Naphthol was the internal standard. Postcolumn hydrolysis with sodium hydroxide of carbaryl and some other A -methyl-carbamate pesticides has also been employed in measuring crop residues of these compounds. The analytical column used was octyl-modified silica. Elution was... 

Application of the phosphorus-specific detection (see Sections 3.8.2 and 8.2.1.2) described by Vaeth et al. [142] allows the use of the AS7 column for the analysis of higher condensed phosphates. A mixture of potassium chloride and EDTA [143] is used as an eluent. The potassium chloride concentration determines retention EDTA is added only for improving peak symmetry. However, postcolumn derivatization with ferric nitrate, as mentioned above, cannot be applied in this case because the Fe(III) ions of the derivatization reagent form... 

The column is then eluted with benzene and 2 ml fractions of the eluent are collected as soon as the product appears in the eluent. The presence of the product is detected by means of the color change in the collected eluent after adding 1 drop of 2% ferric chloride and 2 drops of 5% potassium ferricyanide solution. 

B. 2,2-(Trimethylenedithio)cyclohexanone. A solution of 3.02 g. (0.02 mole) of freshly distilled 1-pyrrolidinocyclohexene, 8.32 g. (0.02 mole) of trimethylene dithiotosylate4 (Note 2), and 5 ml. of triethylamine (Note 3) in 40 ml. of anhydrous acetonitrile (Note 4), is refluxed for 12 hours in a 100-ml., round-bottom flask under a nitrogen atmosphere. The solvent is removed under reduced pressure on a rotary evaporator, and the residue is treated with 100 ml. of aqueous 0.1 N hydrochloric acid for 30 minutes at 50° (Note 5). The mixture is cooled to ambient temperature and extracted with three 50-ml. portions of ether. The combined ether extracts are washed with aqueous 10% potassium bicarbonate solution (Note 6) until the aqueous layer remains basic to litmus, and then with saturated sodium chloride solution. The ethereal solution is dried over anhydrous sodium sulfate, filtered, and concentrated on a rotary evaporator. The resulting oily residue is diluted with 1 ml. of benzene and then with 3 ml. of cyclohexane. The solution is poured into a chromatographic column (13 x 2.5 cm.), prepared with 50 g. of alumina (Note 7) and a 3 1 mixture of cyclohexane and benzene. With this solvent system, the desired product moves with the solvent front, and the first 250 ml. of eluent contains 95% of the total product. Elution with a further 175 ml. of solvent removes the remainder. The combined fractions are evaporated, and the pale yellow, oily residue crystallizes readily on standing. Recrystallization of this material from pentane gives 1.82 g. of white crystalline 2,2-(trimethylenedithio)cyclo-hexanone, m.p. 52-55° (45% yield) (Note 8). 

Fig. 1. Simultaneous separation and detection of anions and cations on a latex agglomerate column. Column Dionex HPIC-CS5 cation exchange column (250X2 mm) with precolumn HPIC-CG5 (50 X 4 mm) eluent 0.5 mM copper sulfate, pH 5. 62 flow rate 0.5 ml/min sample volume 20 gl containing 0.1 m M of each ion detection two potentiomet-ric detectors equipped with different ion-selective electrodes in series. Peaks (1) chloroacetate, (2) chloride, (3) nitrite, (4) benzoate, (5) cyanate, (6) bromide, (7) nitrate, (8) sodium, (9) ammonium, (10) potassium, (11) rubidium, (12) cesium, (13) thallium. Reprinted with permission from [10].

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)...

To a solution of previously dried l-[[2-carboxy-3-(2-dimethylaminoethyl)-5-indolyl]methanesulphonyl]-pyrrolidine (1.6 g 0.0442 moles) in anhydrous quinoline (75 ml) and under atmosphere of nitrogen, cuprous oxide (160 mg 0.0011 moles) was added. The reaction mixture was heated to 190°C for 15 minutes, stirred to room temperature, poured into a mixture of 1 N hydrochloric acid (150 ml) and ethyl acetate (50 ml), shaken and decanted. The aqueous solution was washed several times with ethyl acetate, then solid sodium bicarbonate was added until pH = 7.8, and washed with n-hexane to eliminate the quinoline. The aqueous solution was made alkaline with solid potassium carbonate and extracted with ethyl acetate. The organic solution was dried (Na2S04), the solvent removed under reduced pressure when a dark oil was obtained (1.3 g yield 92%). This product was purified by column chromatography with silica gel and methylene chloride ethanol ammonium hydroxide (60 8 1) as eluent and a white foam (0.8 g) of l-[[3-(2-dimethylaminoethyl)-5-indolyl]methanesulphonyl]-pyrrolidine was obtained. To a solution of the above product (0.8 g) in acetone (30 ml), a few drops of hydrogen chloride saturated dioxan solution, were added. The precipitated solid was collected by filtration, washed with acetone and dried to give l-[(3-(2-(dimethylamino)ethyl)-5-indolyl)methanesulphonyl]-pyrrolidine hydrochloride (0.75 g). Melting point 218°-220°C. 

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