Study On The Determination Of Silver By Hydride Generation And Atomic Fluorescence Spectrometry

The waste silver recycling, food and health, scientific research as well as the exploration of silver mineral and so on need a simple, effective, sensitive and inexpensive method to accurately measure trace or ultra-trace level of silver. This work was aimed to this need to develop a simple and rapid procedure for determination of silver with hydride generation (HG) and atomic fluorescence spectrometry (AFS).This thesis includes four chapters. In the first part, a systematic summary was made, which was mainly on the development of AFS, the structure of the instrument, and application of HG in atomic spectroscopy.The second part of the thesis developed a HG-AFS method to measure trace or ultra-trace level of silver using a SK-2003 double channel atomic fluorescence spectrometer. Under optimized operating conditions detection limit (3σ) was 1.13 ng/mL, which is prominent compared with other atomic spectroscopic method, such as atomic emission spectrometry (AES) and flame atomic absorption spectrometry (FAAS).Further study was concentrated on improving the sensitivity of developed HG-AFS method for silver determination. From an accidental phenomenon of the experiment, it was discovered that oxygen can remarkably enhance the fluorescence signal of silver with the method developed in Chapter 2. It was expected that hydrogen peroxide could have similar result to enhance the AFS signal intensity of silver. The experiment shown that 1% hydrogen peroxide in sample solution gives the best signal to noise ratio. The detection limit of 0.60 ng/mL was obtained under optimized operating conditions when 1% hydrogen peroxide added in sample solution, which was improved two times compared with that when there is no hydrogen peroxide spiked into the sample solutionAt the end of the thesis, suggestions were given on the following investigation of developed procedure on determination of silver with HG-AFS. Surely, it's a simple and good way for mechanism survey of silver hydride generation with AFS, and also silver HG technique can give a excellent detection ability for measurement of ultra-trace level of silver.