Hypersil

There have been compared the methods of mycotoxin control in food products with aflatoxin as an example, using both HPLC method with fluorescent detecting on the apparatus Thermo FL 3000 with a column BDS Hypersil C 2.1x150, as well as a chromatodensitometry method on the apparatus CAM AG TLS Scanner 3. 

Figure 13.9 Coupled-column RPLC-UV (215 nm) analysis of 100 p.1 of an extract of a spiked soil sample (fenpropimoiph, 0.052 mg Kg ). LC conditions C-1, 5 p.m Hypersil SAS (60 m X 4.6 mm i.d.) C-2, 5 p.m Hypersil ODS (150 m X 4.6 mm i.d.) M-1, acetonitrile-0.5 % ammonia in water (50 50, v/v) M-2, acetonitrile-0.5 % ammonia in water (90 10, v/v) flow-rate, 1 ml min clean-up volume, 5.9 ml transfer volume, 0.45 ml. The dashed line represents the cliromatogram obtained when using the two columns connected in series without column switcliing. Reprinted from Journal of Chromatography A, 703, E. A. Hogendoom and R van Zoonen, Coupled-column reversed-phase liquid cliromatography in envir onmental analysis , pp. 149-166, copyright 1995, with permission from Elsevier Science.

The extraction of colorless catabolites from samples is usually performed by homogenizing the ground tissue in 20 to 100 mM K3PO4 buffer (pH 7.0) and methanol (1 1, v/v) - or 0.1 M Tris-HCl, pH 8.0 and methanol (1 4 v/v) followed by centrifugation and analysis by RP-HPLC, either directly or after concentration on a C18 SepPak cartridge. A reversed phase system with a C18 Hypersil ODS... 

Fig. 5.5 Chromatogram ofchlor-prothixene hydrochloride CRS which contains 2.7 % ofthe f -isomer. (Column 4 x 120 mm hypersil BDS [3 pm]. Mobile phase 6.0 g potassium dihydrogen phosphate, 2.9 g sodium lauryl sulphate, 9.0 g tetrabutylammonium bromide 550 ml water, 50 ml methanol and400 ml acetonitrile, flow rate 1.5 ml/min and detection wavelength 254 nm.)...

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

Figure 14 Fractionation of 40-60-base oligodeoxyadenylates. Column 0.41 x 5 cm column packed with cross-linked and methylated PEI on Hypersil , 3 p. Eluent 50 mM potassium phosphate, 15% acetonitrile, pH 5.9 with a gradient from 200-500 mM ammonium sulfate. Flow rate 0.5ml/min. Oligomers of deoxyadenylic acid were fractionated up to a degree of polymerization of 60.180 (Reproduced with permission of Academic Press from Drager, R. R. and Regnier, F. E., Anal. Biodiem., 145, 47, 1985.)...

The chromatographic procedure may be carried out using (a) a stainless steel column (10 cm x 4.6 mm) packed with stationary phase C (3 pm) (Hypersil ODS in suitable), (b) as the mobile phase with a flow rate of 2 mL/min a 0.6% (w/v) solution of ammonium acetate in a mixture of 300 volumes of acetonitrile, 320 volumes of methanol and 380 volumes of water, and (c) a detection wavelength of 235 nm. 

Even when the trifluoroaeetyl-(+)-camphor ligand is linked to a solid support (Hypersil silica 205d), if retains its activity both in terms of yield and optical induction. 

The application from van der Hoeven et al. (1997) used an ADS cartridge online SPE to measure cortisol and prednisolone in plasma and arachidonic acid in urine. A precolumn packed with a C18 alkyl-diol support (LiChrosphere RP-18 ADS, 25 /an, Merck) was used. To reduce run time, column switching was programmed as heart-cut , diverting only the analyte fraction into the analytical column. Another LiChrosphere column (125 x 4 mm inner diameter, Merck) handled separation. After the injection of 100 fiL plasma, the lower limit of detection for prednisolone was 1 ng/mL while cortisol was readily quantitated at its endogenous level of 100 ng/mL. The run time was 5 min. For arachidonic acid, a Hypersil ODS column (200 x 3.0 mm inner diameter, 5 /.an) was used. The injection volume was 200 //I. and run time was 9.5 min. The detection limit was 1 ng/mL and recovery was 77%. 

Column Hypersil Pep5-C18 (4.6 x 150mm) solvent A 0.06% aqueous TFA solvent B 0.06% TFA in 90% aqueous acetonitrile flow rate 1.20mL min x effluent monitored at 220 nm. 

In order to determine the applicability of retention indices, based on the alkyl arylketone scale, as the basis of a reproducible method of reporting retentions, the separation of 10 barbiturates and a set of column test compounds were examined on an octadecylsilyl bonded silica (ODS-Hypersil) column with methanol-buffer of pH 8.5 as eluent [100]. The effects on the capacity factors and retention indices, on changing the eluent composition, pH, ionic strengthened temperature, showed that the retention indices of the barbiturates were much less susceptible to minor changes in the eluent than the capacity factors. 

Fig. 2.3.4. Normal-phase chromatograms of commercial mixtures of alkylphenol ethoxylates (a) OP[EO]g/g (b) NP[EO]2 (c) NP[EO]4 (d) NP[EO]10. Column 100 X 4.6 mm2 Hypersil 3 NH2 (3 pm), gradient elution with re-hexane-2-propanol-H20,...

Datta et al. [40] used pressurised fluid extraction to extract ground fish tissue, and the resulting extract was purified on aminopropyl silica (APS) extraction cartridges. With no further sample preparation, NP and its ethoxylates, up to nonylphenol pentaethoxylate, were quantified using normal phase (APS Hypersil) HPLC with fluorescence detection. 

Fig. 25. Effect of percentage of acetonitrile (A) and methanol (B) on electroosmotic mobility in a packed column. (Reprinted with permission from [56]. Copyright 1997 Elsevier). Conditions capillary column 100 pm i. d., total length 33.5 cm, active length 25 cm packed with 3 pm CEC Hypersil C18, mobile phase organic modifier-water+4% 25 mmol/1 TRIS pH = 8, voltage 30 kV, temperature 20 °C, marker thiourea... 

The enantiomeric purity of protected amino acids used in peptide synthesis can be determined by pre-column partial deprotection followed by derivatization with Marfey s reagent (116). The Marfey diastereoisomers can be easily resolved and determined by RP-HPLC using an ODS-Hypersil column288. Fifteen amino acids collected from mammalian tissues were derivatized with Marfey s reagent and subjected to two-dimensional TLC. Each individual spot (enantiomeric mixture of a diasteroisomer) was then resolved by RP-HPLC. Except for tyrosine (46) and histidine (117), subnanomole quantities of enantiomers could be analyzed289,290. 

Fig. 3.89. Separation of the six anionic dyes under gradient conditions in 5 pm Hypersil ODS, 100 X 3 mm i.d. column. Eluent (first solution) 25 mM TBAN03, 25 mM acetate buffer pH 4.7 (second solution) methanol. Flow rate, 0.7 ml/min injection volume, 20 pV, gradient indicated in the Figure sample solution, mixture of anionic dyes, concentration of each 25 pg/ml Absorption detection at 500 nm. Reprinted with permission from R. M. Seifar et al. [150].

The nitrobenzene oxidation mixture was analyzed using the HPLC method. 0.2 mL of the stock solution was pipetted into a 25 mL volumetric flask and acetonitril-water (1 2 vA ) was added to it. About 20 gL of the sample solution was next injected into the HPLC system (Shimatzu) equipped with a Hypersil bond C,g coluitm (particle size 5 gL, 25 x 4.6 mm i.d.) to quantitatively determine the vanillin component while another component was determined qualitatively. Acetonitril-water (1 8) containing 1% acetic acid was used as an eluent with a flow rate of 2 tuL/min. The eluent was then monitored with an UV (ultraviolet) detector at 280 ran [6]. 

Biotransformation samples were analysed by HPLC using a C18 Hypersil ODS 5p column (125 mm x 3 mm) and a Hewlett Packard HP 1100 instrument equipped with an Agilent 1100 series diode array detector. The samples were isocratically eluted using an aqueous phosphoric acid (0.1 % v/v)/methanol mix (70 30 (v/v)) at a flow rate of 0.5 mL min ... 

The aim of this review is to summarize the difficulties likely to be encountered in the LC separation of basic solutes, which include the majority of pharmaceutical and also many biomedically important compounds. An answer to the problem of the separation of the cinchona alkaloids, fit for purpose, was obtained on the Hypersil column by adding the silanol blocking agent hexylamine to the mobile phase, which allowed the extra separation power of the smaller particle column to be exploited [3]. However, alternative solutions to the problem, which will be explored in this review, are more appropriate in particular circumstances there is no universal solution that is applicable in all cases. The present review will concentrate on the most recent developments in this subject for the past few years. Further background information can be found in earlier reviews by the present author [4,5] and by Snyder [6]. 

---