No abstract

A preliminary study of interfacing of a high pressure liquid chromatography instrument with a continuous source atomic fluorescence detector is reported. The chemical system investigated is the acetylation reaction of ferrocene by acetic anhydride. The retention data from the conventional UV molecular absorption detector are in excellent agreement with those obtained using the atomic fluorescence detector monitoring the iron fluorescence signal. The metal-containing compounds are more easily quantitated with the fluorescence detector, both because it does not respond to purely organic interferants co-eluting with the compounds of interest and because the integrated response is insensitive to the chemical form of the compound.High pressure liquid chromatography (HPLC) detectors have been reviewed by several authors (1-7). Detectors based on refractive index, UV or visible light absorption, heat of absorption, electrical conductivity, flame ionization and

No abstract

No abstract

Simultaneous multielement atomic absorption spectroscopy has not become a common laboratory workhorse for elemental analyses despite recent advances in instrumentation. Two major obstacles preventing its implementation are the sometimes severe matrix interferences which occur in some pulsed atomizers and the limited working range of atomic absorption spectroscopy compared to the wide linear dynamic range of inductively coupled plasma-atomic emission spectroscopy. Use of a constant temperature furnace in conjuction with techniques such as peak width at fixed height, random dilutions with element rationing, and monitoring two or more wavelengths of different sensitivities of an element are effective methods for eliminating or reducing these obstacles. Determination of trace zinc in unweighed samples of reagent grade CdCl2·2.5H2O and the determination of lead in unknown volumes of blood using hemoglobin iron as the internal standard are examples of analyses performed on the dual channel monochromator used in this work. Problems in selecting appropriate compromise conditions of atomization are exemplified in work done on solid samples. Although full recoveries of Zn and Cd were obtained at 1800 K in biological samples, low recoveries for Zn were obtained in NBS coal fly ash at this temperature. Atomization at 2100 K was necessary to restore full recovery.