Sensitivity enhancement for slotted quartz tube flame atomic absorption spectrometry using a gas screen

摘要

Slotted Quartz Tube (SQT) is a simple device that provides a sensitivity enhancement of 2-5 times in Flame Atomic Absorption Spectrometry (FAAS) depending on the element. A Gas Screen-Slotted Quartz Tube (GS-SQT) was designed to further increase sensitivity. For this purpose, two slotted gas chambers were fixed on the left and right sides of a burner head and Ar gas was supplied into these chambers perpendicular to the light path to produce two thin layers of gas screen. It was observed that these Ar screens can move up the flame tails in two ends of SQT. In addition to an increase in sensitivity by the use of SQT, Ar screen resulted in a further improvement in characteristic concentrations, C_0, by a factor of 1.60 for Cd, 2.01 for Co, 1.42 for Cu, 1.94 for Mn, 1.86 for Ni, 1.78 for Pb, 1.62 for Se, and 1.09 for Zn. In addition to the enhancement in sensitivity, gas screen also helps by protecting the spectrometer from the adverse effect of using slotted quartz tube. The system is very simple and low-cost; it can be produced and applied easily.