Controlled-dispersion flow analysis with atomic-absorption detection for the determination of clinically relevant elements

Abstract
Flow injection analysis offers many advantages as a sample introduction technique for atomic-absorption spectroscopy. The methods of sample injection, however, are wasteful of sample. Controlled-dispersion analysis is a technique that dispenses with the need for injection septa or valves and consumes a minimum amount of sample. Methods are described for the determination of lithium, magnesium, calcium, copper and zinc in body fluids. As the sample volume can be easily varied over a wide range, calibration can be performed using only one standard. The methods are precise and easily automated and have a sample throughput greater than 120 samples h–1. A unique method of economising on reagent is also described.