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Altex injection system

Apparatus. The major components in the HPLC system (Figure 2) include a Varian HPLC pump (model 5000, Varian Assoc., Walnut Creek, CA), Altex injection valve (model 210, Beckman Inst., Fullerton,... [Pg.198]

Apparatus Pumping systems used in these studies for high-performance columns were a Varian 8500 syringe pump and a Varian 5000 isocratic pump. An Altex IlOA was employed for the con-trolled-pore glass (CPG) columns. Waters Associates model 401 refractometers were used on all instruments. Stagnant mobile phase was kept in the reference side of the refractometer. Samples were injected with a Rheodyne 70-10 injection valve using a 20yl loop (lOOyl for CPG columns). [Pg.209]

The trend toward automatic injection will become predominant with increasing routine application. Currently, satisfactory injection devices are only available for GC septum injection from Hewlett-Packard, Varian, etc. These have been adapted to HPLC with good results [6] within the general limitations of septum injection. Automatic injection usually results in better reproducibility with relative standard deviations of less than 1% and external standardization can be used [6]. Automatic systems based on loop injection have been announced by several manufacturers, e.g. DuPont, Varian, Altex. [Pg.82]

Figure 3 shows a schematic of the FIA system and details the thin-layer transducer cell, which contains the poly(3-methylthiophene) anion sensor electrode(s). Electrochemical detection in the amperometric mode was employed for the FIA/EC (flow injection analysis with electrochemical detection) studies. A typical potential used was +1.00 volts vs. Ag/AgCl reference electrode. The FIA-EC system consisted of an Altex lOOA double reciprocation pump and a Rheodyne injector (Cotai, CA) with either a 20 or 50 microliter sample loop. Constant potentials were applied using the herein described DWEP, which is software controlled. The electronically transduced signals are converted from analog to digital by use of A/D and D/A converter circuits. The option exists to automatically save the data on the computer or print the results as the experiment progresses. [Pg.140]


See other pages where Altex injection system is mentioned: [Pg.21]    [Pg.490]    [Pg.260]    [Pg.544]   
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