| Monitoring of heavy metal elements in seawater has been highly concerned. National standards for the analysis of heavy metals were each given two to four kinds of different analytical methods. In practice, due to the different laboratories for the determination of an analysis method with a different element selected, the results may vary. This phenomenon reduces the comparability of survey data of offshore area seawater, which easily leads to the facts that some marine chemical behaviors of trace elements are difficult to study, that evaluating the level of pollution reliably is limited. In this paper, according to the actual situation and with the members of National Offshore Environmental Monitoring Network as study groups, the practical applications of analytical methods of marine heavy metal monitoring are studied. It mainly consists of two parts. One is to study the practical application of monitoring methods of heavy metals in seawater, the other is to find and recommend the analytical method most suitable for practical application, through different experiments of analyzing the total chromium, copper, lead, cadmium, zinc, and mercury in seawater.1. Distributing questionnaires to the members of offshore network. The current ratio of actual work when analyzing heavy metals in seawater in domestic stations by different analy-tical methods is drawn, through collecting, reorganizing and summarizing the information in questionnaires. Meanwhile, further research is determined, which is the comparable experi-ments of Total Cr, Cu, Pb, Cd, Zn and Hg by GF-AAS,DPC, ASV,FAAS,CAAS and AFS.2. Comparing the GF-AAS and DPC of measuring Total Cr in seawater, in order to investigate the practical application in laboratories of these two methods. The MDL of Total Cr in seawater are0.17μg/L and0.11μg/L by GF-AAS and DPC. The standard addition recoveries are102.3%～103.5%and98.2%～101.6%, and the relative standard deviations in laboratory are4.52%～5.42%and4.90%～5.31%respectively.3. Comparing the GF-AAS and ASV of measuring Cu, Pb and Cd in seawater, in order to investigate the practical application in laboratories of these two methods. The MDL of Cu in seawater are0.10μg/L and2.33μg/L by GF-ASS and ASV. The standard addition recoveries are101.5%～107.7%and87.2%～147.8%, and the relative standard deviations in laboratory are4.56%～6.59%and11.60%～19.41%～respectively. The MDL of Pb in seawater are0.15μg/L and0.38μg/L by GF-ASS and ASV. The standard addition recoveries are100.7%～101.0%and97.8%～143.2%, and the relative standard deviations in laboratory are3.71%～8.56%and16.69%～18.72%respectively. The MDL of Cd in seawater are0.15μg/L and0.02μg/L by GF-ASS and ASV. The standard addition recoveries are98.0%～98.8%and99.8%～107.1%, and the relative standard deviations in laboratory are4.11%～5.02%and8.22%～8.71%respectively.4. Comparing the FA AS and ASV of measuring Zn in seawater, in order to observe the practical application in laboratories of these two methods. The MDL of Zn in seawater are1.73μg/L and1.06p.g/L by FAAS and ASV. The standard addition recoveries are101.1%～103.7%and138.7%～145.9%, and the relative standard deviations in laboratory are2.93%～3.12%and16.76%～17.11%respectively.5. Comparing the CAAS and AFS of measuring Hg in seawater, in order to observe the practical application in laboratories of these two methods. The MDL of total mercury in seawater are0.010μg/L and0.008μg/L by CAAS and AFS. The standard addition recoveries are97.1%～97.2%and97.0%-99.2%, and the relative standard deviations in laboratory are0.67%～0.99%and0.86%～1.92%respectively.6. According to the experimental data, considering the MDL, accuracy and precision of the methods, pre-treatment processes, complication of the methods, it is recommended as follows.Measuring Total Cr, Cu, Pb and Cd by GF-AAS,measuring Zn by FAAS,measuring Hg by AFS in seawater is recommended. |
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