Heptanesulfonic acid

Fig. 2.98. Separation at 520 nm of red wine (Cabernet Sauvignon) extract before (a), and after (b) addition of 20 mm heptanesulphonic acid to the mobile phase. In (a), the two broad peaks at approximately 40 and 55 min are anthocyanins before heptanesulfonic acid addition and in (b), the two peaks at approximately 12 and 15 min are the same anthocyanins after heptanesulphonic acid addition. Reprinted with permission from J. A. Kennedy et al. [233].

Analysis of vitamin content of food materials appears to be a developing field. B vitamins in rice were analyzed using a mobile phase which contained pentanesulfonic acid and heptanesulfonic acid (558). Although the peaks were not sharp, the separation of the vitamins was satisfactory. Vitamin D in fortified milk has b n analyzed after removal Of cholesterol and carotenes in a preliminary cleanup (559, 540). Vitamin A has been analyzed in margarine, infant formula, and fortified milk (541, 542). Reports of the analysis of other vitamins in food are few to te but this mode of analysis can be expected to rapidly expand in the future in light of the variety of vitamin determinations in formulations which have been done (see Section VIII,F,l). 

Hupka et al. [29] developed a method for the determination of morphine and its phase II metabolites, morphine-3-beta-D-glucuronide and morphine-6-beta-D-glucuronide in the blood of heroin victims. The method is based on immunoaffinity SPE, RP-HPLC isocratic separation (mobile phase 90% lOmmol KH2PO4, 2mmol 1-heptanesulfonic acid, adjusted to pH 2.5 with H3PO4 and 10% acetonitrile flow rate 1.5 mL/min), and laser-induced native fluorescence detection. 

TCA extn, liq-liq partn, SPE cleanup, liq-liq partn, 1-heptanesulfonic acid addn... 

Solvent A MeOH/HzO/ HOAc (70 29 1) contg 0.5% heptanesulfonic acid... 

SW column using methanol water (1 9) containing 0.1 M KH2P04 and 0.01 M 1-heptanesulfonic acid for elution, and a MicroPak MCH-10 RP column, eluted with a methanol/water gradient solvent system. 

A reversed-phase HPLC post-column ion-pair extraction system was developed by Kim and Stewart [71, 72] for the analysis of carboxylic acid drugs and their salts (sodium formate, sodium acetate, 3-bromopropionic acid, 6-aminocaproic acid, 11-bromoundecanoic acid, 1-heptanesulfonic acid, / -n i t rophcny 1 acetic acid, sodium benzoate, sodium salicylate, valproic acid, probenecid, naproxen, ketoprofen, ibuprofen, mefenamic acid, flufenamic acid, and cefuroxime sodium) using a-(3,4-dimethoxy-phenyl)-4,-trimethylammoniummethylcinnamonitrile methosulfate... 

The assay involves the isolation of the pyrrole by ion-paired, reversed-phase HPLC (Hypersil-SAS) with a mobile phase of methanol and water (45 155, v/v) and 0.005 mol/L 1-heptanesulfonic acid (PIC B-7). The radioactive product was detected by scintillation counting. The separation obtained when the compounds were in distilled water is shown in Figure 9.57a. However, when the analysis was carried out on freeze-dried samples, the salts present led to the results shown in Figure 9.57b. 

The assay involves the separation of ALA from PBG by ion-paired, reversed, phase HPLC (Hypersil SAS) with a mobile phase of methanol-water (22 78, v/v) and PIC B-7 (0.005 M 1-heptanesulfonic acid) adjusted to pH 3.5. An internal standard of 2-methyl-3-carbomethoxy-4-(3-propionic add)pyrrole was used. All three compounds were readily separated in 6 minutes (Fig. 9.58). Detection was at 240 nm. 

A reverse phase ion-pairing HPLC method was developed by the submitters for analysis. Chromatographic conditions A 10-pL sample (0.1 mg/mL in acetonitrile) is injected onto a suitable liquid chromatograph equipped with a Waters Symmetry Shield RP18 column, 250 x 4.6 mm, 5 pm particle size at 40°C with a mobile phase of 0.404 g/L heptanesulfonic acid, sodium salt -i- 0.1% phosphoric acid (Component A, pH 2.2) and acetonitrile (Component B) at a flow rate of 1.0 mL/min, programmed with a linear gradient from 95 5 A B (v/v) to 30 70 A B (v/v) over 20 min. Detection is achieved by UV at 300 nm. The retention time is approximately 10 min. 

Heptanesulfonic acid RP2 RPa RP18 MeOH—H20—HAc Phenothiazine bases and sulfoxides 7)... 

A, S,codeine, papaverine,quinine, caffeine, ephedrine Various drugs Retention behaviour basic drugs in ion-pair HPLC pBondapak C18 pBondapak Phenyl pBondapak CN pBondagel Chromegabond C8 Chromegabond CgH 300x4 0.005M heptanesulfonic acid in H,0-MeOH-AcOH(50 49 1) (pH <-0) 50... 

A Various drugs Separation anticholinergic drugs uBondapak C18 300x3.9 0.01M heptanesulfonic acid -ACN(65 35) 27... 

Coc.pseudococ,a11ococ, allopseudococ Separation of diastereoiso-mers(Fig.4.8) Nucleosil C18,5ym 150x4.0 THF-H 0(1 4) containing 0.005M heptanesulfonic acid and 2 AcOH 46... 

Column Nucleosil C18 5 pm (150x4.0 mm ID), mobile phase tetrahydrofuran - water (1 4) containing 0.005 M n-heptanesulfonic acid and 2% acetic acid, flow rate 1.0 ml/min, detection UV 235 nm. Peaks 1, cocaine 2, pseudococaine 3, allococaine 4, allopseudococaine. (Reproduced with permission from ref. 46, by courtesy of Recueil des travaux chimiques des Pays-Bas)... 

Column yBondapak C18 (300x4 mm I.D.), mobile phase 0.005 M heptanesulfonic acid in methanol - water - acetic acid (40 59 1), pH ca 3.5, flow rate 2 ml/min. 

Smith et aiused ion-pair chromatography to separate apomorphine and related alkaloids. A diphenylsilane column was used in combination with methanol - acetonitrile -0.02 M aqueous potassium dihydrogen phosphate - 0.03 M citric acid (pH 3.25) containing 0.001 M sodium dodecylsulfate (36 9 55). The system allowed baseline separation of apomorphine, apocodeine, isoapocodeine and the internal standard N-n-propylnorapomorphine or boldine. Dodecylsulfate as counter-ion gave better results than heptanesulfonic acid. Without the addition of a pairing-ion, tailing was observed. 

Soni and Dugar84 analyzed opiates with reversed-phase ion-pair chromatography using the ion-pair chromatography no tailing for the alkaloids was observed on octadecylsi lane columns. Tetrabutyl ammonium phosphate and 1-heptanesulfonic acid were used as pairing-ions (Table 7.5). 

RETENTION TIMES (min) OF MORPHINANS FOR DIFFERENT SOLVENT SYSTEMS40 (CONTAINING 0.005 H n-HEPTANESULFONIC ACID). 

Column yBondapak C18 (300x4 run ID), mobile phase 0.005 M heptanesulfonic acid in methanol -water - acetic acid (40 59 1) (pH ca. 3.5), flow rate 2 ml/min, detection UV 254 nm. Peaks 1, morphine 2, codeine 3, thebaine 4, noscapine 5, papaverine. (Reproduced with permission from ref. 38, by courtesy of Journal Association official analytical chemists)... 

C,M,No,P,T,H,OAcH, Amphetamines, AcC,Q,S,Tp,caf,coc, barbiturates, ergot alkaloids local anaesthe tics Ion-pair HPLC of drugs of abuse (Table 7.3) pBondapak C18 300x4 0.005M Heptanesulfonic acid in Me0H-Ac0H-H20(40 l 59)(pH 3.5) 38... 

C,M,P,H,AcC,OAcM,oxyC, oxyM.diHCone.diHMone, noroxyM.nalo Separation of illicit samples (Table 7.5) pBondapak C18 300x4 MeOH-aq. 0.01M Bu.N pH 7.5(47 53) MeOH-aq. 0.01M heptanesulfonic acid pH 3 (35 65) changing to(55 45) after 20 ml (... 

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