RESUMEN
A rapid UV-Vis spectrophotometric method was proposed to determine the concentration of DMP in aqueous solutions. The linear concentration range of DMP solution at the range of 250ï½400 nm is 0.5ï½70 mmol·L(-1). At 275 nm, the linear fitting equation is A=0.030 7c+0.133 0 with a correlation of 0.980 9. The detection limitation is 9.46×10-5 mmol·L-1, the RSD (n=6) of the method were at the range of 0.100%ï½0.612%. The recovery ratio for salt solutions sample is 95%ï½104%. Temperature, pH, and coexisting K(+), Na(+), Mg(2+), Cl(-), Br(-), I(-), SO(2-)(4) ions do not affect the detection. The coexisting CO(2-)(3) and HCO(-)(3) ions can be eliminated with acidification. The results showed that the proposed method is simple in pretreatment process and has high accuracy and precision. It is a quick measurement method of DMP concentration in water solution, and can be used to measure DMP concentration in reverse flotation tail liquid and reverse flotation material pulp.
RESUMEN
The high similarity of MO and EO made it difficult to measure concentration of MOD and EOD. In this paper, dual wavelength spectrophotometry was used to determinate the concentration of MOD and EOD, which was proved to be fast and accrate. 429.00 nm and 469.50 nm were selected as detemination wavelengthes at pH 12. And the influences of Na+ and Cl- on determination of MOD and EOD were surveyed. The standard equations were A429 = 0.003 47 + 0.061 cm + 0.056 46 C(E) and A469.50 = 0.002 8 + 0.074 37 cm + 0.083 94 c(E) . Recovery of standard additions of MOD and EOD were larger than 95%, and relative standard deviation of standard equations were less than 2%. The addition of NaCl has little effect on recovery of standard additions and relative standard deviation of this method.
