Sulphonic acids chromatographic

Phosphorus and Silicon in Waters, Effluents and Sludges [e.g. Phosphorus in Waters, Effluents and Sludges by Spectrophotometry-phosphomolybdenum blue method. Phosphorus in Waters and Acidic Digests by Spectrophotometry-phosphovanadomolybdate method. Ion Chromatographic Methods for the Determination of Phosphorus Compound, Pretreatment Methods for Phosphorus Determinations, Determination of silicon by Spectrophotometric Determination of Molybdate Reactive Silicon-1 -amino-2-naphthol-4, sulphonic acid (ANSA) or Metol reduction methods or ascorbic acid reduction method. Pretreatment Methods to Convert Other Eorms of Silicon to Soluble Molybdate Reactive Silicon, Determination of Phosphorus and Silicon Emission Spectrophotometry], 1992... 

Metabolites formed during the decolourization of the azo dye Reactive red 22 by Pseudomonas luteola were separated and identified by HPLC-DAD and HPLC-MS. The chemical structures of Reactive red 22 (3-amino-4-methoxyphcnyl-/fhydroxyl-sulphonc sulphonic acid ester) and its decomposition products are shown in Fig. 3.92. RP-HPLC measurements were carried out in an ODS column using an isocratic elution of 50 per cent methanol, 0.4 per cent Na2HP04 and 49.6 per cent water. The flow rate was 0.5 ml/min, and intermediates were detected at 254 nm. The analytes of interest were collected and submitted to MS. RP-HPLC profiles of metabolites after various incubation periods are shown in Fig. 3.93. It was concluded from the chromatographic data that the decomposition process involves the breakdown of the azo bond resulting in two aromatic amines [154],... 

Parsons [120] converted sulphonyl chlorides into fluorides prior to GC analysis. A 1-ml volume of a solution of sulphonyl chloride in benzene (ca. 50 mg) and 1 g of potassium fluoride dihydrate were placed in a reaction flask fitted with a reflux condenser. Benzene was refluxed on an oil bath at 105—110°C for about 1.5 h and, after cooling, the benzene solution was injected into the chromatograph or fluorides were isolated by removing benzene. Fluorides of sulphonic acids are more stable than chlorides and their volatility is higher. GC separation was executed with satisfactory results on 3.8% of SE-30. 

Baker and Boyce [122] determined isomers of toluenesulphonic acid as ethyl esters prepared by the reaction with triethyl orthoformate. About 0.1 ml of sulphonic acid was added to a known amount of toluene (12 ml) and the water produced was removed by azeotropic distillation with about 5 ml of toluene. o-Terphenyl (0.05 g in 3 ml of toluene) was added as an internal standard, followed by a 20-fold excess of triethyl orthoformate, and the solution was refluxed for 15 min. After this period the reaction proceeds quantitatively and the reaction mixture can be injected directly into the chromatograph. The separation was carried out on 3% of OV-101. 

A mixture of 2.2 g. (20 mMol) of crystalline resorcinol, 3.05 g. (20 mMol) (+)- ra/is-/j-menthadien-(2,8)-ol-(l) and 0.4 g. (2 mMol) of p-toluene sulphonic acid monohydrate in 50 mL. of benzene is heated under reflux for 2 hours. The resulting solution is dissolved in 50 mL. of diethyl ether. The ether is extracted once with dilute sodium bicarbonate solution. The ether phase is dried and evaporated. 5.1 g. of a yellow oil is obtained. This oil is chromatographed on 250 g. of silica gel and eluded with benzene. After distilling off the benzene under high vacuum, there is obtained 778 mg. of (-)-l-hydroxy-6,6,9-trimethyl-6a,10a- rans-6a,7,10,10a-tetrahydrodibenzo(b,d)-pyran. This compound has an RF value (silica gel thin layer chromatogram in chloroform) of 0.35 and a boiling point of 155°C./0.001 mmHg. 

Selective removal of bromine from 3/3,5,6/3-tribromo-5a-cholestane to give 3/3-bromocholest-5-ene was achieved by reaction with [T -C5H5Cr(N02)2]2. The reactions of 11/3-hydroxy-steroids with dialkylaminosulphur trifluorides depend on the substitution at C-9 and involve the formation of intermediate (11) (Scheme 1) (see ref. 232). Selective dehydration with FeCls adsorbed on silica gel allowed the conversion of 5a-cholestane-3/3,5-diol into cholesterol (80%) and 3i3-acetoxy-5a-cholestane-5,25-diol into 3/S-acetoxycholest-5-en-25-ol (72%). Other examples and additionally the hydrolysis of 5,6a-epoxy-5o -cholestan-3/3-ol to the 3/3,5a,6/8-triol (90%) were reported. Chromatographic alumina is reported to effect smooth elimination of sulphonic acids from the esters with less than normal rearrangement. Thus lanosteryl tosylate and cycloartenyl tosylate gave the respective A -compounds in yields of 90% and 45% respec-... 

P.H. Kuijpers, T.K. Gerding and G.J. de Jong, Improvement of the Liquid Chromatographic Separation of the Enantiomers of Tetracyclic Eudistomins by the Combination of a P-cyclodextrin Stationary Phase and Camphor-sulphonic Acid as Mobile Phase Additive, J. Chromatogr., 625(1992) 223. 

An alternative method is to use an ion chromatograph, where the sample is ashed for about 10 h at 750°C, the residue dissolved in HNO3, diluted with distilled water to a given volume and an aliquot eluted with 0.02% methane sulphonic acid (CH3SO3H), which forms the Na salt and the conductivity is then checked against known Na standards. 

Stable esters coming formally from alkynols and carboxylic, sulphonic or dialkyl phosphoric acids were prepared for the first time via alkynyliodonium salts with the corresponding anion. Several alkynyl carboxylates were obtained by anion exchange of alkynyl iodonium tosylates the initially formed salts, PhI+C=CR RCO2, were converted spontaneously into the esters on elution through a chromatographic column packed with an anion-exchange resin (Pol+ArCOj) ... 

Diaminodiphenyl sulphone and related drugs are chromatographed as 4,4 -diiodo derivatives. The amino groups are diazotized by treatment with nitrous acid and substituted with iodine, and the resulting derivative provides a high ECD response [568]. 

Fig. 11.2.9. Amino acid analysis using a conventional analyser. Chromatographic conditions colunm, Dionex DC-6A (300x4.6 mm I.D.) mobile phase, sodium citrate, three-buffer programme detection, post-column reagent ninhydrin (absorbance 1 full scale). Peaks 1, cysteic acid 2, aspartic acid 3, methionine sulphone 4, threonine 5, serine 6, glutamic acid 7, proline 8, glycine 9, alanine 10, half cystine 11, valine 12, methionine 13, isoleucine 14, leucine 15, Y-leucine 16, tyrosine 17, phenylalanine 18, ammonia 19, lysine 20, histidine 21, arginine. Reproduced from Beckman information catalogue, with permission.

Fig, 11.8.6. HPLC determination of nicotinic acid in (a) normal serum and (b) serum fortified with nicotinic acid (50 nmol/ml). Chromatographic conditions stationary phase, Lichrosorb RP-18 (Merck) (5 jam) (150x4 mm I.D.) mobile phase, acetonitrile-water (4 6 v/v) containing 5 mM sodium 1-hexane sulphonate flow rate, 1.3 ml/min temperature, ambient detection, pre-column derivatisation, excitation at 325 and 335 nm and emission at 395 and 390 nm, respectively. 1, nicotinic acid 2, 2-chloronicotinic acid. Reproduced from Tsuruta et al. (1984), with permission. 

---