HT-HPLC

The review is organized in the following sections. The chromatographic theory relevant to EFLC and HT-HPLC is first described. Next a detailed description of the physicochemical properties of EEL mixtures is included. This is followed by a survey of the scope of liquid chromatography (LC) techniques that are presently using the attributes of EELs. Finally, a discussion of future applications of EF-HPLC is included. 

Figure 9 A ubore separation cycle time comparison. Separation was performed on a Waters Alliance ) HT HPLC System (Waters Corporation, Milford, MA) using a 1.0 by 50mm 3.5 micron particle size Symmetry C18 column (Waters Corporation, Milford, MA) at 60°C. The mobile phase consisted of 0.1% phosphoric acid as the A solvent, and acetonitrile as the B solvent, run as a linear gradient from 10-95% B over 2 minutes at 300 pL/inin. UV detection at 220nm, and a 2 pi, injection was used. Peaks 1-6 (O.lmg/mL each in 50/50 methanol/water) are uracil, caffeine, primidone, phenacetin, benzophenone and biphenyl, respectively.

Fig. 24 Coupling of the HT-HPLC system to the ELSD for concentration detection and the LC Transform interface. (Reprinted from [156] with permission of Wiley-VCH)...

To summarize, all techniques used for polyolefin characterization have advantages and disadvantages. Some information can be obtained more reliably from one technique and some other fi om other techniques. One really has to decide on the problems to be addressed using a given technique. Nevertheless, 2D-HT-HPLC seems to be one major technique to be used for polyolefin analysis in the future due to its ability to provide MMD as a function of CCD of the sample which is not possible by other approaches. 

Recently, it has heen demonstrated that high-temperature HPLC (HT-HPLC) can he used as an alternative method for the determination of the CCD of semicrystalline copolymers of ethylene and polar comonomers. ... 

The chip micro reactor ([R 6]) was only one part of a complex serial-screening apparatus [20]. This automated system consists of an autosampler (CTC-HTS Pal system) which introduces the reactant solutions in the chip via capillaries. A pumping system (p-HPLC-CEC System) serves for fluid motion by hydro dynamic-driven flow. A dilution system [Jasco PU-15(5)] is used for slug dilution on-chip. The detection system was a Jasco UV-1575 and analysis was carried out by LC/MS (Agilent 1100 series capLC-Waters Micromass ZQ). All components were on-line and self-configured. 

Mass specttometer, TSQ 7000 with API electtospray source and gradient HPLC input (Finnigan MAT, San Jose, CA, USA) or equivalent Soxtec exttaction unit, HT 1043 with exttacAon cups (Tecator, Hoganas, Sweden) or equivalent... 

Figure 7.4 Dose-response effects of MDMA on extracellular levels of endogenous 5-HT (left panel) and DA (right panel) in rat nucleus accumbens. Male rats undergoing in vivo microdialysis received i.v. injections of 1 and 3 mg/kg MDMA at 0 and 60 min, respectively. Dialysate levels of 5-HT and DA were assayed by HPLC-ECD. Data are mean SEM, expressed as pg/5 pi sample, for N = 6 rats/group. Baseline levels of 5-HT and DA were 0.22 0.03 and 1.44 0.24 pg/5 pi, respectively. Significant with respect to pre-injection control (P < 0.05 Duncan s). See Baumann et al.39 for methods.

Depletions of 5-HT in forebrain regions as measured by HPLC-ECD 10-40 mg/kg, 4 days s.c., twice daily, 2 weeks Commins et al.68... 

We developed a staggered parallel HPLC system with a CTC HTS PAL autosampler equipped with trio valves. The system consists of four (six if gradient is needed) independent HPLC pumps. Parallel analysis is achieved by an offset dual-stream system with a time delay that allows efficient staggering of MS acquisition times. 

Their method included a Waters 2795 Alliance HT (high throughput) HPLC system with an integrated autosampler. The stationary phase was a Supelco C18 column (250 x 4.6 mm, 5 fim). The mobile phase consisted of solvent A (water containing 2mM ammonium acetate and 0.1% formic acid) and solvent B (methanol containing 2mM ammonium acetate and 0.1% formic acid). The mobile phase was delivered at a flow rate of 0.6 mL/min in a step gradient mode 50% solvent B from 0 to 0.4 min and 100% solvent B from 0.4 to 0.8 min. 

HPLC High-performance liquid chromatography HT Distilled mustard combined with bis(2-chloroethyl sulfide) monoxide IDLH Immediately dangerous to life or health kg Kilogram... 

Biogenic amines are of great interest to researchers because of their potential roles in several psychiatric and neurological disorders. They include dopamine (DA), noradrenaline (NA), 5-hydroxytryptamine (5-HT, serotonin), histamine, and trace amines such as 2-phenylethylamine (PEA), tyramine, octopamine, phenylethanolamine, and tryptamine (Coutts and Baker, 1982). Although GC assays for DA, NA, and 5-HT are available, HPLC analysis with electrochemical detection has for many years now been the method of choice for analysis of these neurotransmitter amines. 

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