“One-drop method” in flame atomic absorption spectrometry

Abstract

The use of a small sample volume in flame atomic absorption spectrometry is tested. A drop of sample solution taken into Teflon cup with micro-pipet is nebulized through ordinary capillary tube. A minimum sample volume giving the same sensitivity as that obtained by the conventional procedure can be estimated. from the sample flow rate, peak height, and overall response time of apparatus including pen-speed of recorder. The measurement with the estimated minimum volume or more can be carried out with excellent reproducibility and linearity of calibration curve. Even with the volume less than the minimum estimated, elements can be determined with the fairly good results. The detection limits (S/N=2) obtained with 100 μl sample solution are given for 11 elements in concentration and absolute amount. The present method was applied to the determination of 6 elements in NBS-SRM 1577 Bovine Liver after decomposition with a mixture of nitric and perchloric acids in a sealed Teflon vessel. Analytical results obtained agree well with the data reported. The one-drop method gives the advantages of use of commercially available apparatus without any modification, reduction in sample size, simple sample preparation, time-saving, good accuracy, and high precision.