Zorbax ODS

Chromatographic conditions elution with 50 50 methanol/water solvent at the rate of 1.5 ml,/min through a DuPont Zorbax ODS column using a Waters R-401 Refractive Index Detector. 

Quantitative HPLC analysis was carried out on a Spectraphysics 8720 chromatography system, a rapid scan detector by Barspec on a Zorbax ODS column with acetonitrile water 75/25 as the eluent. 

A stainless steel column (4.6 mm internal diameter by 250 mm length) packed with 7 micron Zorbax ODS (Dupont) was equilibrated with 82 % Acetonitrile in water at a flow rate of 2.0 ml/min. provided by a Spectra Physics Model 87(X) pump and controller. The effluent was monitored at 230 nm using either a Tracor UV-Visible detector Model 970A or a Jasco Uvidec UV detector Model 1(X)-V. Peaks were recorded and calculated on a SpectraPhysics recording integrator. Model 4200 or Model 4270. Samples of 0.5 mg/ml in toluene were applied to the column automatically with a Micromeritics Autosampler Model 725 equipped with a 10 pi loop. 

Partisphere C-18 Zorbax ODS Partisil 5 ODS-3 Hypersil ODS (HP) Ultrasphere ODS Supelcosil LC-18 Hypersil ODS... 

Detectability may be a significant problem with homologous series of unsaturated compounds, particularly //-alkanes. For these compounds, refractive index detection or evaporative light-scattering, both of which are described elsewhere in the book, may be of use. Indirect photometry is a useful detection scheme for compounds that do not absorb in the UV. Acetone, methylethyl ketone, methyl propyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, and acetophenone are added to an acetonitrile/water mobile phase, generating a negative vacancy peak when the nonchro-mophoric analyte emerges and a positive peak if the ketone is adsorbed and displaced.70 Dodecyl, tetradecyl, cetyl, and stearyl alcohols also have been derivatized with 2-(4-carboxyphenyl)-5,6-dimethylbenzimidazole and the derivatives separated on Zorbax ODS in a mobile phase of methanol and 2-propanol.71... 

Axelsen and Vogelsang have reported the separation of gramicidins A, B and C by HPLC using Zorbax ODS (5 pm) eluted at 60 C with methanol-5 mM ammonium sulfate (37 13) 200. ... 

NP chromatography is unable to separate vitamin D2 from vitamin Dj. So it is usually used as semipreparative chromatography [527-531]. Instead, RP chromatography is able to resolve vitamin D2 and Dj, thus it is widely applied as aualy tical chromatography. Mattila et al. [532] describe a two dimensioual LC procedure. The sample is saponified and an NP semipreparative column is used before the quantification in a tandem column set (Zorbax ODS x Vydac 201 TP54 CIS). 

Column - Dupont Zorbax ODS, 5 pm particle diameter, 25 cm long x 0.46 cm ID... 

Figure 3. Standards recovered from 10 mL of distilled-deionized water on an ODS precolumn. Peak identities 4, 0.14 pg of caffeine 5, 0.20 pg of pentachlorophenol 7, 0.061 pg of m-nitroandine 8, 0.15 pg of atrazine 9, 0.40 pg of quinoline 10, 0.26 pg of 2,6-dichloroaniline 11, 0.14 pg of N-nitrosodiphenylamine and 12, 0.055 pg of pyrene. Conditions for concentration 10-mL sample enriched on an ODS-packed precolumn. Analytical separation was on Zorbax ODS, 250-mm by 4.6-mm i.d. column. Mobile-phase gradient was 100% pH 7,0.1 M acetate buffer for 2 min followed by ramp to 90% acetonitrile/10% pH 7, 0.1 M acetate buffer (v/v) in 20 min at 1.0-mL/min flow rate. Detection was at 254 nm. (Reproduced with permission from reference 18.)...

Nelis and De Leenheer (180) used isocratic NARP-HPLC with Zorbax ODS (a monomeric ODS stationary phase with a 20% carbon loading) and a mobile phase of acetonitrile/dichlorometh-ane/methanol (70 20 10) to separate nine carotenoids spanning a wide polarity range. This classic separation was achieved by virtue of the fact that the Zorbax ODS material supplied at that time was nonendcapped. The carotenes were retained by hydrophobic interaction with the ODS... 

Fig. 12 Analytical HPLC of fractions from a saponified chicken sample isolated by semipreparative HPLC. (A) Vitamins D2 (internal standard) and D3. Tandem columns, Zorbax ODS + 5 /nm Vydac 201 TP54 Cl8 (250 X 4.6-mm ID) mobile phase, methanol/water (96 4), 1 ml/min absorbance detection, 264 nm. (B) 25-Hydroxyvitamin D2 (internal standard) and 25-hydroxyvitamin D3. Tandem columns, 5 /nm Spherisorb S5NH2 (250 X 4.6 mm) + 10 /nm /nPorasil (300 X 3.9 mm) mobile phase, hexane/2-propanol (97 3), 1 ml/min absorbance detection, 264 nm. (Reprinted in part with permission from Ref. 205. Copyright 1995, American Chemical Society.)...

Reversed-phase chromatography Zorbax ODS 5 pm MeCN/CH2Cl2 contain-... 

Methanol/ion pair/ water gradient 250 X 4.6-mm-ID Zorbax ODS or Shimpack ODS No Ambient 270 26... 

Zorbax ODS Ethyl acetate/methanol/water 436, chi, pheo Spinach 100... 

Zorbax ODS A acetonitrile/methanol (70/30) 437 chi, chlid, pheo, Beans 78... 

C-18 reverse phase column, such as Zorbax ODS or equivalent. Acetonitrile/water (70 30) to 100% acetonitrile in 15 min. 

HPLC column Zorbax ODS mobile phase 80/20 methanol/ water flow rate 1 mL/min. 

Alternatively, sample analyzed by HPLC UV detection recommended at 195 nm HPLC column Zorbax ODS or equivalent mobile phase water, flow rate 1 to 2 mL/min. 

---