International Sorbent Technology

Biotage, Uppsala, Sweden [International Sorbent Technology, Ltd., Glamorgan, UK]... 

Bond Elut (Agilent) and CBA ISOLUTE (International Sorbent technology) both representing an irregular end-capped mixed-mode phase of a weak cation exchanger (carboxylic acid) and a mid-polarity sorbent. /V-butyl-scopolamine was extracted accordingly from equine urine [78], Elution of analytes was achieved by the use of a methanolic solution acidified either with 1 M HC1 [54] or 1 % formic acid [78] allowing competition between QTA and hydronium ions. Recoveries were between 96 and 103 % [54] (Table 4). 

ISOLUTE Array plates. International Sorbent Technology Ltd., UK.www.rit-5pe.com. 

Figure 1.1. Process of solid-phase extraction. (Reproduced in somewhat modified form from the catalog pages of International Sorbent Technology, Ltd., copyright. ISOLUTE and 1ST are registered trademarks of International Sorbent Technology, Ltd.)...

It is quite important to know the pore size of the silica gel (which controls surface area), the amount of liquid phase or functional groups bonded to the silica, the type of derivatization reagent (mono- or trifunctional), and the extent of endcapping. This information was realized by some of the manufacturers of SPE products thus, they supply customers with quality control and quality assurance (QA) data of their SPE products. Figure 2.8 shows an example of such a QA report from 1ST (International Sorbent Technology). 

International Sorbent Technology, SBD-1 from J. T. Baker, and the Oasis HLB poly(divinylbenzene-co-A-vinylpyrrolidone) polymer of Waters. All of these polymers contain some trace of hydrophilic character to improve their wetting characteristics for good mass transfer, but yet the polymers still have high capacities for polar organic compounds. 

The solvents used, acetonitrile, ethanol, 2-propanol, 1-propanol, 2-butanoI, ethyl acetate, toluene, acetone and hexane, were of pro-analysis grade. All the solvents were purchased from Merck (Darmstadt, Germany), except ethanol (99.5 %), Miich was obtained from Kemetyl (Haninge, Sweden). MilliQ-water was obtained from a purification system (Millipore). Nitrogen, (99.996 % by volume) was from AGA, (Stockholm, Sweden). Methanol of HPLC quality (Merck) was used as a mobile phase. Isolute sorbent (pelletized diatomaceous earth. International Sorbent Technology, Great Britain) was used as adsorbent in the initial studies. 

Vac Master SPE Vacuum Manifold (International Sorbent Technology, Ltd.) connected to a vacuum pump via a water trap 1.0-mL glass volumetric flasks with ground glass stoppers 10-pL microliter syringe (Hamilton Co.) for injection into the GC 10 ppm trifluralin reference stock standard dissolved in iso-octane 10 ppm 1,2,4-trichlorobenzene (IS) dissolved in MeOH or methyhert-butyl ether (MTBE)... 

Vacmaster vacuum manifold to conduct solid-phase extraction (SPE) from International Sorbent Technology the manifold enables 10 extractions to be performed at the same time Water trap and associated vacuum tubing to be used with the Vacmaster... 

These and other sorbents are supplied in prepacked columns. Analy-tichem (Varian Sample Preparation Products) Bond Elut, International Sorbent Technology (Jones Chromatography) Isolute and Waters Sep-Pak are all well-known names. The sorbents are also available in bulk, and a wide range of accessories is available, such as Luer stop-cocks, vacuum pumps, manifolds and regulators. The sorbents supplied by Varian and International Sorbent Technology appear to be identical, but... 

Jones Chromatography, Hengoed, Mid-Glamorgan, for supplying literature about the products of International Sorbent Technology and Varian Sample Preparation Products. 

The cleanup method was adapted from Andrzejewski et al. OASIS-HLB columns (Waters, 6 cc (300 mg). International Sorbent Technology Ltd) were conditioned with 3.5 mL methanol followed by 3.5 mL water. The solvents used for the column conditioning were discarded. The cartridge was loaded with 1.5 mL sample extract... 

Silica, Isolute Si, International Sorbent Technology, 2 g in a 12-mL SPE cartridge... 

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