Study On Determination Of Xanthates And Dibutyl Dithiophosphate In Water Samples

There is a sulphur atom in xanthates and dibutyl dithiophosphate, and the ionized solution containing anion with sulphur may actively collect sulphide ores, so this kind of compounds is widely used as a collector in flotation. Combination of flotation reagents is an important research direction. Kinds of combination of xanthates and combination of xanthates and dibutyl dithiophosphate are extensively applied in actual mineral processing. Subsequently, the investigation of flotation mechanism and optimum dosages is a popular topic. In addition, flotation effluent without treatment may seriously damage our environment. Therefore, establishing methods of simultaneous determination of xanthates and dibutyl dithiophosphate has a very important practical significance.Xanthates are strong ionic compounds and can not be retained on reverse-phase chromatographic column. Three xanthates complexed with Cu(Ⅱ) may create six hydrophobic compounds, then based on that, three xanthates were determined by reverse-phase high performance liquid chromatography with pre-column derivation. The influence of the composition and proportion of the mobile phase, the flow rate, the column temperature, the detection wavelength and the injection volume on the separation and determination of six components were studied. The optimal conditions included a Kromasil C18(200×4.6mm,5μm) column. A system composed of methanol and water acted as the mobile phase using a isocratic elution style, and the proportion of methanol and water was92:8. The ultraviolet detection wavelength was285nm and the column temperature was30℃The flow rate was1.0mL/min and the injection volume was10.0μL. Meanwhile, the optimized derivative conditions were determined as follows:water sample was added by1.00mL HAc-NaAc (pH5.4),1.00mL CuSO4(0.2%, m/v), then, shaken up evenly and placed for5min, after that,2.0g NaCl and2.0g ethyl acetate were added to extract the derivatives using whirlpool mixer for2min, standed for5min. The organic phase was filtered by0.45μm filter membrane before HPLC determination. Under the optimal conditions, the linear correlation coefficients of working curves ranged from0.9993to0.9999. The detection limits were1～3×10-3μg/mL. The average recoveries of samples were91.6%～107%and the relative standard deviations were2.0%～12%. The simultaneous determination of ethyl, butyl and amyl xanthates in laboratory flotation effluents could be performed in16minutes.A ratio spectra derivative spectrophotometry method was established for the simultaneous determination of the butyl xanthate and dibutyl dithiophosophate in laboratory flotation water samples. After optimizing of instrument parameters and calculation method, the optimal experimental conditions were as follows:ultra violet spectrum of1μg/mL butyl xanthate was used as divisor for calculateing the ratio-derivative of spectrum of the water sample for quantitative analysis dibutyl dithiophosophate at248nm; in the same way, using1μg/mL dibutyl dithiophosophate as divisor for quantitative analysis butyl xanthate at291nm,310nm. Under the optimal conditions, butyl xanthate and dibutyl dithiophosophate showed a good linear relationship at a range of0.02～20.9μg/mL, r=0.9996and0.9993, respectively. The detection limits were0.008and0.01μg/mL. Laboratory flotation water samples were determined. The average recoveries of butyl xanthate and dibutyl dithiophosophate were92.0%and96.5%, respectively, and the relative standard deviation were1.2%and1.9%.Results showed the HPLC method was sensitive and rapid, and could be used for the simultaneous separation and determination of three xanthates according to their alkyls. The ratio spectra derivative spectrophotometry method was easy and low cost, and was suitable for the determination of butyl xanthate and dibutyl dithiophosophate in laboratory flotation water samples without complicated pre-treatment.