环境监测大题(外国英语资料).docVIP

环境监测大题(国外英文资料) Methods and principles of two different types of pollutants in water are described respectively. 1. determination of mercury; Dithizone spectrophotometry in acidic medium: water to 95 degrees with the Potassium Permanganate solution and potassium persulfate (oxidant) solution. The inorganic and organic mercury into two valent mercury, with hydroxylamine hydrochloride solution reducing excess oxidant, adding dithizone solution and mercury ion reaction orange chelate, chloroform extraction, adding dithizone excess alkali wash solution, measuring the absorbance at the wavelength of 485nm, the quantitative standard curve method. 2. cold atomic absorption spectrometry after digestion by water: various forms of mercury into the two mercury, Mercury will by stannous chloride reduction of two for elemental mercury, the mercury volatilization characteristics at room temperature by adding nitrogen to load it into the cold atomic absorption mercury analyzer to measure the absorbance characteristics of light having a wavelength of 253.7nm. The absorbance and mercury standard to compare quantitatively, in a certain range of concentration and absorbance is proportional to the concentration of. Features: dithizone spectrophotometric method is strict and complex operation and not the hydroxylamine hydrochloride excess on reagent purity requirements demanding light half of the black box operation, suitable for the determination of industrial waste water and polluted surface water quality determination of concentration of 2~40ug|L was determined by cold atomic absorption spectrometry is simple, less interference and high sensitivity detection quality the concentration of 0.1~0.5ug|L is suitable for all kinds of water mercury Two. The principle and method of determination on Potassium Permanganate index of the CODcr, its characteristics and applicability CODcr: potassium dichromate method in strong acid solution with a certain amount of potassium dichromate as reducing