Instrumentation
Development of Hydride Generation Methods for Atomic Saectroscopic Analysis -*C-a.md-
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A FRESH DESIGN FOR THERMAL CONDUCTIVITY DETECTORS The new, single filament thermal conductivity detector developed for the HP 5880A GC requires none of the usual operating adjustments (balance, zero, etc.). It is quite insensitive to temperature; a 100°C change in detector temperature produces no change in baseline. The detector can be turned off when not in use to extend filament life. If the detector is maintained at operating temperature while off, the baseline will be stable about 20 seconds after it is turned back on. Warm-up from a cold turn-on takes less than 30 minutes.
Please circle Reader Service Nurr ber 160 for a copy of this paper.
A new technical paper describes detector design and operation with both capillary and packed columns. The novel “fluidic switch” design and the cell construction are shown.
AUTOMATIC HPLC: TRACE ANALYSIS OF WATER POLLUTANTS HPLC is well-suited for identification of water pollutants less volatile than those usually analyzed by GC. Relatively dirty samples may be analyzed without workup, and large amounts of water can be injected directly into the column without harming the column or detector. The 1084B Liquid Chromatograph, equipped with 79875A programmable, variable-wavelength UV-VIS absorption detector, allows stopped-flow spectral scanning of each component peak. Comparison of resulting UV absorption spectra with reference data provides excellent identification. Trace amounts of water contaminants may be concentrated for improved detection, either by choosing a solvent of low elution strength to concentrate components on the analytical column, or by using a short, pellicular precolumn which is 896 A
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then backflushed onto the analytical column. The latter method is easily automated by using a switching valve; analysis time is substantially reduced because flow rate through the precolumn may be increased during the concentration step.
ANALYTICAL CHEMISTRY, VOL. 51, NO. 8, JULY 1979
Sensitivity to various component may be optimized through use of thl programmable, variable wavelengt’ detector; each component i detected at its wavelength of mar imum absorption. For more inform2 tion, circle Reader Service No. 161
RIplO DRUQ O V E R W E ANALYSIS BY P m S
AUTOMATIC PURQE AND TRAP ANALVSIS
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