| With the rapid and continued development of society and economy,the excessive use of industrial chemicals and exploitation of energy have resulted in severe environmental pollution,especially to the pollution of environmental water.Arsenic and lead as toxic substances exist widely in nature,and they can induce a variety of diseases and even cancer.According to the regulation of Chinese National Standard of drinking water,the maximum concentration levels of arsenic and lead should be controlled at less than 10 ?g L-1,which make a challenge for the determination of arsenic and lead in environmental water.Photo-chemical vapor generation(PVG)as a novel sample introduction approach has many inherent advantages with respect to conventional hydride generation(HG),e.g.,low molecular weight organic acid(LM WO A)as a PVG reagent with the features of low cost,favorable stability and non-pollution;less interference from transition metal ions;enhancing the stability of ICP torch due to less hydrogen generated in the PVG process;low blank response and high signal-noise ratio.In the present work,the novel methods are developed for the determination of inorganic arsenic and lead in environmental water by atomic fluorescence spectrometry(AFS)or inductively coupled plasma-mass spectrometry(ICP-MS)coupled with a PVG sample introduction approach,respectively.In the first chapter,the state of the art is presented in the progress,application,mechanism and efficiency of PVG,as well as common analytical methods for the determination of arsenic and lead.In the second chapter,an analytical method is developed for the determination of inorganic arsenic in environmental water by PVG-AFS.In the experiment,ferric ion is served as a sensitizer of PVG for the first time,giving rise to the fluorescence intensity of As(?)increased by a factor of 10.The factors governing the PVG efficiency are optimized,including the variety and concentration of low molecular weight organic acid,irradiation time,concentration of ferric ion sensitizer and flow rate of carrier gas.Furthermore,the mechanism of sensitizer,PVG efficiency of As(?)and reduction condition of As(V)are investigated,respectively.Under the optimal conditions,a linear range of 0.5-100.0 ?g L-1 is achieved for arsenic,along with a detection limit of 0.05 ?g L-1(3?,n = 11)and a RSD value of 2.0%(25?g L-1 As(?),n = 11).To demonstrate the accuracy,the present method is applied for the determination of total arsenic content in three environmental water samples and certified reference material GSB-Z50004-200431,giving rise to spiking recoveries of 92-98%for environmental water and reasonable agreement between the certified and the found values for certified reference material.In the third chapter,an analytical method is developed for the determination of lead in environmental water by PVG-ICP-MS.In the experiment,the conditions of PVG are optimized and the potential interferences of coexisting substances with lead determination are investigated in detail.Under the optimal conditions,a linear range of 0.1-100.0 ?g L-1 is achieved for lead,along with a detection limit of 0.005 ?g L-1(3?,n = 6)and a RSD value of 5.6%(25 ?g L-1 Pb,n = 6).To demonstrate the accuracy,the present method is applied for the determination of lead content in two environmental water samples and the certified reference material GSB 07-1183-2000-201228 and GSB 07-1183-2000-201229,giving rise to spiking recoveries of 98-105%for environmental water and reasonable agreement between the certified and the found values for certified reference material.In the fourth chapter,the characteristics and significances of the present methods are summarized. |
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