Eluents ammonium nitrate

Uranium ores are leached with dilute sulfuric acid or an alkaline carbonate [3812-32-6] solution. Hexavalent uranium forms anionic complexes, such as uranyl sulfate [56959-61-6], U02(S0 3, which are more selectively adsorbed by strong base anion exchangers than are other anions in the leach Hquors. Sulfate complexes are eluted with an acidified NaCl or ammonium nitrate [6484-52-2], NH NO, solution. Carbonate complexes are eluted with a neutral brine solution. Uranium is precipitated from the eluent and shipped to other locations for enrichment. Columnar recovery systems were popular in South Africa and Canada. Continuous resin-in-pulp (RIP) systems gained popularity in the United States since they eliminated a difficult and cosdy ore particle/leach hquor separation step. 

R. Gill, M. D. Osselton, R. M. Smith, and T. G. Hurdley, Retention reproducibilty of basic drugs in high-performance liquid chromatography on silica columns with methanol-ammonium nitrate eluent, J. Chromatogr., 386 54 (1987). 

Eluent. Methanol ammonium nitrate buffer solution (90 10). To prepare the buffer solution add 94ml of strong ammonia solution and 21.5ml of nitric acid to 884 ml of water and adjust to pH 10 by the addition of strong ammonia solution. 

Christiansen et al. developed an HPLC method of screening Norwegian mushrooms for the presence of psilocin and psilocybin. The alkaloids were extracted from powdered dried mushrooms with methanol which contained 10% IN ammonium nitrate (Christiansen et al. 1981). The recovery of psilocybin was at least 98%, whereas the recovery of psilocin was not reported. The analytes were separated on an unmodified silica column using an alkaline eluent (Christiansen and Rasmussen 1983). After separation, the effluent was split to UV and FL detectors, and an EC detector was connected downstream of the UV detector. Psilocybin was identified and determined by both UV and FL detection. EC was optimized for psilocin due to its low concentration in the mushroom. The detection limit of psilocin by EC was 100 and 250 times lower than by UV and FL, respectively. Psilocybin gave only a small response by EC, since it is optimally oxidized at a higher potential. By this method, it was found that Conocybe cyanopus and Pluteus salicinus also contained psilocin and psilocybin (Christiansen et al. 1984). 

Figure 2.5 Hydrodynamic voltammograms generated by repeat injections of physostigmine ( ) and its hydrolysis product, the phenol eseroline (o). Chromatographic conditions Column 250 x 4.6 mm(i.d.) Spherisorb S5W Eluent methanol-aq. ammonium nitrate (1.0 mol L , pH 8.5) (90 + 10) Flow rate 0.75 mL min Detection glassy carbon electrode (GCE). The half-wave potentials (from the fitted curves) were - -0.69 V and - -0.21 V vs Ag/AgCl.

Figure 3.13 Analysis of physostigmine using the ESA Coulochem [PGEs, guard cell (positioned between column outlet and analytical cell) +0.8 V, Ej —0.2 V, E2 + 0.1 V vs Pd]. Column 150x4.6 (i.d.) mm Spherisorb S3W silica Eluent acetonitrile-methanol-aq. ammonium nitrate buffer (0.1 mol pH 9.5) (45 + 45 + 10) Flow-rate 0.75 mL min Injection 50 jiL methanol containing 1 ng physostigmine (1).

Leroy and Nicolas reported that atropine extracted from belladonna powder could be assayed by HPLC-ED, but the only antimuscarinic drug that appears to have been assayed in biological samples by HPLC-ED is hyoscine (scopolamine. Figure 6.14). An unmodified silica column was used with acetonitrile-aq. ammonium nitrate (0.1 molL pH 8.9) (9 -f 1) as eluent. Hyoscine, apohyoscine (a hyoscine metabolite) and iV-ethylnorhyoscine (Figure 6.14), the internal standard, were detected at PGEs (-1-0.9 V V5 Pd). The method was applied to urine, which was extracted with toluene under alkaline conditions. The analytes were concentrated by adsorption onto acid-prepared cyanopropyl-modified silica SPE columns and eluted with HPLC eluent. The LoD was lpgL (5mL sample). 

Figure 8.104 Trace analysis of chlorate in drinking water with ESI-MS/MS detection. Separator column lonPac AG9-SC eluent 65mg/L ammonium nitrate/MeOH (10 90 v/v) flow rate 1 mL/min detection ESI-MS/MS in the negative MRM mode (83/67, 85/69) sample volume 5 ml sample drinking water with...

A mixture of ferrocenyl alcohol (1 0.5 mmol), nucleophile with activated hydrogen atom (2 0.5 mmol) and ceric ammonium nitrate (CAN 5 mol %) in acetonitrile (2 mL) was stirred at room temperature for an appropriate time (0.25-120 h for varying substrates). Upon completion, monitored by TLC, the solvent was evaporated under the reduced pressure. The crude product was purified by flash column chromatography with ethyl acetate and petroleum ether as eluents to afford ferrocene derivative 3 with good yield (52-99%). Each of the products was characterized by means of spectral studies including IR, H NMR, NMR and HRMS. 

Di(ethynylphenyl)benzoquinone (13). 12 (0.300 g, 0.886 mmol) and THF (6 mL) were added to a 25 mL round bottom flask containing a stir bar. A solution of ceric ammonium nitrate (1.46 g, 2.658 mmol) in water (3 mL) was slowly added to the flask and allowed to stir for 15 min. Water was added and the organic materials were extracted with CH2CI2. Flash column chromatography (silica gel using 1 1 hexane CH2Cl2 as eluent) afforded the desired product (0.129 g, 47 %). IR (KBr) 3047.5, 2203.0, 1716.2, 1655.3,... 

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. 

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)...

Fig. 8.19. Coordination ion spray mass spectrum of estradiol extracted from the reversed-phase CEC—CIS-MS separation of estrogenic compounds. Column, 250 x 0.1 mm i.d. packed with 3 pm GROM-SIL ODS-O AB eluent, 4 mmol/1 ammonium acetate, pH 9.0, 50% acetonitrile applied pressure, 8 MPa applied voltage, 15 kV detection, ESI-MS, 0.85 s/spectrum sheath liquid, 100 pg/ml aqueous silver nitrate, 3 pl/min mass spectrum extracted from a reconstructed ion chromatogram of the separation of estriol, estradiol, equiline, and estrone. (Reproduced from ref. [104] with permission of Wiley-VCh).

While the type of available eluent depends upon the detection method being applied in anion exchange chromatography, a corresponding classification is not necessary in cation exchange chromatography. For the separation of alkali metals, ammonium, and small aliphatic amines, mineral acids such as hydrochloric or nitric acid are typically used as eluents, independent of whether the subsequent conductivity detection is performed with or without chemical suppression. The concentration range lies between 0.002 mol/L and 0.04 mol/L. Bachmann et al. [141] employed cerium(III) nitrate in very low concentrations as the eluent for the indirect fluorescence detection of alkali metals. 

Fig. 8-14. Simultaneous detection of nitrite, nitrate, and ammonium in a KC1 soil extract. - Separator column IonPac CSS eluent 0.035 mol/L KC1 flow rate 1 mL/min detection (A) UV (215 nm), (B) fluorescence after reaction with OPA injection 50 pL sample of a 1 10 diluted KCI soil extract (10%).

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