Separator column LiChrosorb

Fig. 5-13. Ion-pair chromatographic separation of inorganic anions on a chemically bonded reversed phase. — Separator column LiChrosorb RP 18 (10 xm) eluent 0.002 mol/L TBAOH + 0.05 mol/L phosphate buffer (pH 6.7) flow rate 2 mL/min detection direct conductivity injection volume 20 pL solute concentrations 1000 ppm each of fluoride, chloride, sulfate, nitrite, bromide, dichromate, and nitrate (taken from [26]).

Figure 6.69 Selectivity comparison between an ODS phase and an OmniPac PCX-100 exemplified with the separation of choline and acetylcholine, (a) Separator column Lichrosorb RP-18 eluent 5 mmol/L heptanesulfonic add (pH 4)/MeCN (99 1 v/v) flow rate 1 mU/min ...

Figure 8.62 Separation of ADAM derivatives of a mixture of long-chain fatty acids. Separator column Lichrosorb RP8,5 pm column dimensions 250 mm X 4 mm i.d. eluent MeCN/water (90 10 v/v) flow rate 1.1 mL/min detection fluorescence after derivatization with ADAM excitation wavelength 365 nm emission wavelength 412 nm injection volume lOpL peaks (a) degradation product of the...

FIGURE 5.7 Effects of binary and ternary gradient elution with methanol and acetonitrile on separation selectivity in RP HPLC. Column LiChrosorb RP-C18, 5 pm, 300x4.0mm i.d. flow rate ImL/min UV detection, 254nm. Sample 4-cyanophenol (1), 2-methoxyphenol (2), 4-fluorophenol (3), 3-fluorophenol (4), 3-methylphenol (5), 4-chlorophenol (6), 4-iodophenol (7), 2-phenylphenol (8), and 3-ferf-butylphenol (9). 

In another study, the substrate was 3,4-dihydroxybenzoic acid, and the reaction products were 3-methoxy-4-hydroxybenzoic acid and 3-hydroxy-4-methoxybenzoic acid. The substrate and the two products were separated by HPLC on a reversed-phase column (LiChrosorb) with a mobile phase of 0.05 M acetic acid in methanol-water (1 4, v/v), pH 3.2 Figure 9.12 shows the separation obtained under these conditions. 

Figure 9.101 Separation of AMP (1), ADP (2), and ATP (3) for reaction times of (A) 10 minutes, (B) 20 minutes, and (C) 30 minutes using 0.04 jug/mL creatine kinase. Chromatographic conditions column, LiChrosorb C18 flow rate, 2.0 mL/min temperature, ambient detection, UV 254 nm, 0.04 absorbance unit full scale injection volume, 10 imL. (From Danielson and Huth, 1980.)...

Fig. 2 RP gradient elution separation of 1,2-naphthoylenebenzimidazole alkylsulphonamides. Column Lichrosorb RP-18, 10 pm (300 X 4 mm id). Linear gradients of metbanol in water with a constant gradient range but different gradient volumes (A-C), and with a constant gradient steepness (1.67% metbanol/min) but different initial concentrations of metbanol (D-F). Flow rate= 1 mL/min. Tbe number of peaks agrees with tbe number of carbon atoms in alkyls.

Fig. 11.9. Straight-phase separation of xanthine derivatives Column Lichrosorb Si60 5 urn (300x3 mm ID), mobile phase dichloro-water (936 47 17), flow rate 70 ml/h, detection...

Fig. 11.4.4. Separation of oxime derivatives of saccharides. Chromatographic conditions column, polar-bonded amino column (Lichrosorb NH2) mobile phase, acetonitrile-water (80 20) detection, UV at 220 nm. Peaks are O-methyloximes of 1, D-glucose 2, D-maltose 3, D-cellobiose 4, D-maltotriose. Reproduced from Chen and McGinnis (1983), with permission.

Fig. 11.4.5. Separation of simple saccharides. Chromatographic conditions column, LiChrosorb Si 60 (5 jam) (250x4.0 mm) mobile phase, acetonitrile-water (75 25) containing 0.01% amine modifier flow rate, 3.0 ml/min detection, refractive index. Peaks Ri, ribose X, xylose F, fructose G, glucose S, sucrose Ma, maltose L, lactose Mb, melibiose Mt, maltotriose. Reproduced from Wight and Van Niekerk (1983b), with permission.

Extraction and isolation. The cells were filtered through filter paper and carefully washed with distilled water. The filtrate was extracted with CHjClj (500 ml x3). The CHjClj layer was dried with anhydrous MgS04 and concentrated in vacuo. The oily residue was chromatographed on silica gel column (2 x 50 cm, hexane-diethyl ether, 4 1) and fiirtha-purified by HPLC. The HPLC conditions for isolation of monoterpenes were as follows column, LiChrosorb Si60 (Merdc) 10 mm x 25 cm, solvent hexane-diethyl ether 1 1, flow rate 3.0 ml/min, UV detector at 240 nm. The harvested cells (113 g fr. wt from 10 flasks) were soaked in MeOH (500 ml) and ground. The cells were separated and extracted a second time with MeOH (500ml). The MeOH extracts were evaporated to dryness, and the residue was dissolved in 50 ml of H2O. The residue was chromatographed on XAD-2 column (2.5 x 30 cm)... 

Figure 7.8 Comparison of the chromatographic behavior between Acclaim Mixed-Mode HILIC-1 and LiChrosorb Diol. Separator columns Acclaim Mixed-Mode HILIC-1,5 pm ( ) and LiChrosorb Diol, 5 pm ( ) column...

Figure 11 HPLC separation of flavin analogs (1) ATP (2) 8-hydroxy-FAD (3) FAD (4) 1-deaza-FAD (5) 5-deaza-FAD (6) FMN (7) 1-deaza-FMN (8) riboflavin (9) 5-deaza-FMN (10) 1 -deaza-riboflavin (11) methyl-riboflavin (12) 5-deaza-riboflavin. Column, Lichrosorb RP18, 25 X 1 cm linear gradient between 5 mM ammonium acetate buffer pH 6.0, and methanol. (From Ref. 85.)...

Pantothenic acid/calcium pantothenate in pharmaceutical products and vitamin premixes was also analyzed using low-wavelength ultraviolet (UV) detection (64,66). The vitamin was extracted from tablets or powdered premixes with 0.005 M NaH2P04 buffer (pH 4.5) and separated from other water-soluble vitamins on an aminopropyl-bonded silica column (LiChrosorb NH2) eluted with an acetonitrile-0.005 MNaH2P04 buffer (pH 4.5) (87 13, v/v) and detected at 210 nm. Quantitative recoveries (>95%) and relative standard deviations 0.79% to 2.2% were obtained for multivitamin tablets, vitamin premixes, fortified yeasts, and raw materials. The limit of sensitivity was approximately 1 mg/g sample. The results were compared with those obtained by the standard microbiological procedure. Low levels of calcium pantothenate (<3 mg per tablet) were more precisely analyzed by the HPLC procedure than by the microbiological method. 

Fig. 9.16. HPLC-UV chromatogram of feed premix sample containing nominally 100 ppm Se each as selenite and selenate species. HPLC-UV chromatogram of separation of standard selenite and selenate species (20 ppm Se) under paired-ion, RP conditions C-18 column (10 fita, 15 cm x 3.9 mm i.d.), RP-300 C-8 guard column (7 /im, 3 cm x 4.6 mm), pre-column Lichrosorb Si60 (30 /tm, 2 cm x 3.9 mm) mobile phase of 2.5 niM TBAHS, 0.01 M each dipotassium hydrogen phosphate and potassium dihydrogen phosphate, pH = 6.55 flow rate 0.5 ml min UV detection at 205 nm injections of 50 1 of 20 ppm each Se species as standards. Peak identities 1 = selenite 2 = selenate 3 = system. (Reprinted with permission of the copyright owner. The American Chemical Society and the ACS Symposium Series [50].)...

Use of 10 pm LiChrosorb RP18 column and binary eluent of methanol and aqueous 0.1 M phosphate buffer (pH 4.0) according to suitable gradient elution program in less than 20-min run time with satisfactory precision sensitivity of spectrophotometric detection optimized, achieving for all additives considered detection limits ranging from 0.1 to 3.0 mg/1, below maximum permitted levels Simultaneous separation (20 min) of 14 synthetic colors using uncoated fused silica capillary column operated at 25 kV and elution with 18% acetonitrile and 82% 0.05 M sodium deoxycholate in borate-phosphate buffer (pH 7.8), recovery of all colors better than 82%... 

Collect the precipitated product by filtration and redissolve it in 400 ml of benzene. Repeat steps 4-5 several times to assure complete removal of unreacted TsT. The residual TsT may be detected by HPLC using a 250 X 3.2 mm LiChrosorb (5 pm particle size) column from E. Merck. The separation is done using a mobile phase of hexane, and peaks are detected with a UV detector. 

HPLC analysis of TAGs was applied to olive oils and a limit for LLL was established at 0.5% of the total TAGs and enclosed in the European Commission (EC) Regulation on olive oils, as well as in the related international norms (International Olive Oil Trade Norm [2], Codex Alimentarius Standard [3]). The method performed the separation by RP-HPLC on a C18 Lichrosorb or Lichrosphere column, 25x0.46 cm, 5 J,m of particle size, isocratic elution with acetone/acetonitrile (50/50 v/v) and RI detection. Eigure 19.1 reproduced the HPLC traces annexed to the official method [4] chromatogram A refers to 100% soybean oil, B to a mixture 50/50 soybean and olive, C 100% olive oil. 

Figure F2.3.4 Isocratic HPLC separation of the food reference material carotenoids using Protocol 4. Conditions Lichrosorb Si60, 5 pm, 250 x 4.6 mm column, hexane/dioxane/IPA/TEA (80 20 0.15 0.02) mobile phase, 1.0 ml/min flow rate, visible detection at 450 nm.

Spherisorb columns from Phase Separations (Queensferry, U.K.) LiChrosorb columns from Merck (Darmstadt, F.R.G.) Nucleosil columns from Macherey-Nagel (Duren, F.R.G.) APEX-MF columns from Jones Chromatography (Llan-bradach, U.K.). 

The HPLC separation into geometrical isomers was performed on a 5-yii.m particle size Hi-bar RP Clg LiChrosorb column (250 mm X 4-mm ID). The mobile phase was methanol-2-propanol (3 1 v/v), with AgN03 in a concentration of 0.085 M, at a flow rate of ca. 1 ml/min. The major PN fractions, at a concentration of 20 mg/ml benzene, were injected in volumes of 5-10 fil. 

Fig. 4 HPLC separation of water-degummed and crude sunflower oil phospholipids on a 250 X 4-mm column packed with Lichrosorb Si-60 according to the AOCS method. The mobile phase consisted of hexane, 2-propanol, and acetate buffer of pH 4.2 in a volumetric ratio of 8/8/1 at 2 ml/min. Detection was accomplished by UV absorption at 206 nm. (Reproduced from Ref. 34 with permission of the American Oil Chemists Society.)...

Fig. 3 HPLC separation of carbohydrates in chickpeas. Column (200 X 4.6-mm ID) LiChrosorb NH2 flow rate 1 ml min-1 mobile phase 20% water in acetonitrile. Refractive index detector. Peak assignment 1, fructose 2, glucose 3, sucrose 4, rafflnose 5, maninotriose 6, stachyose 7, verbascose.

Herrmann et al. (24) used ion-pair chromatography for the determination of cyclamate. The efficiency of LiChrosorb RP-18 and Hypersil MOS 3 with a mobile phase of 5 mM tetrabutylammonium p-toluenesulfonate, pH 3.5, mixed with 12% methanol for the separation of cyclamate from other sweeteners was investigated. With the first column, cyclamate separated from saccharin, but the second was the recommended column for the analysis of cyclamate, saccharin, aspartame, and dulcin in a single run. 

Organic acids were separated on a LiChrosorb RP-18 (250-mm X 4.6-mm-ID) column, using the mobile phase 0.005 M ammonium acetate-acetic acid-acetonitrile, at a detection wavelength of 225 or 232 nm. This method can be used for vegetable oils, meat salads, jams, mayonnaise, and mustard (69). After derivatization (benzoylation), it is possible to separate EsHBA with either normal-phase or reverse-phase columns. The normal-phase method showed high efficiency and sensitivity at a detection limit of 0.2 ppm. The preservatives were separated on a LiChrosorb Si 60 column and eluted with isoacetate-diethyl ether-acetonitrile (500 35 0.3). On an RP-18 column, a methanol-water mobile phase was used. Eluents were monitored at 240 nm (70). 

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