Research On Detction Technique For Seawater Trace Heavy Metal

The takeoff of coastal economy and increscent dependence on marine resourcesaggravated the pollution in parts of Chinese inshore waters. Heavy metal pollution aretrend to rise, too. Heavy metal bring great harm to coastal aquaculture and fishing.Final, human health is affected by drinking water, food chain and bioconcentration.Therefore, setting up the real-time seawater monitoring system will be important forquick information-acquisition, pollution spreading-prevention and more important formaintaining marine ecological environment and the marine interests. This article givesa detailed description for seawater heavy metal detection technology and puts forwardthe study of soluble seawater trace heavy metal detection technology and experimentalbased on dual path spectrophotometry. The main contents are as follows.First, the common heavy metal detection methods are analyzed. Thespectrophotometric theory, the multicomponent measuring based on the chemicalmetrology and the spiked-measuring principle are explained detailedly. The advantagesand disadvantages of MLR（Multiple Linear Regression） algorithm, PCA（PrincipalComponent Analysis） algorithm and PLS（Partial Least Squares） algorithm arecompared.Next, characteristics of Zn²⁺, Cu²⁺, Ni²⁺, Cd²⁺are studyed through spectral intheir chromogenic solution. The acidity, dose of chromogenic agent, the temperature,turbidity and salinity are analysed. Also, the measurement sensitivity for every ion isgiven.Once more，the possibility of simultaneous detection for Zn²⁺, Cu²⁺, Ni²⁺, Cd²⁺are verified and infulences from the other ions in are studyed. The orthogonalcorrection and test sets for the analysis of multi-component measurement are setted up.The absorbance added theories for heavy metal ions are researched.Finally, the experimental system of sea water soluble trace Zn²⁺, Cu²⁺, Ni²⁺, Cd²⁺is established. The absorbance fitting results in each wavelength is analyzed and themeasurement range for each ion are carried out. The feasibility and precise of each algorithm are analysed.The measurement results are compared witrh ICP-OES and thethe theories are verified.