Studies On Synthesis And Its Application By Spectrophotometry With New5-Carboxylic-1,2,4-Triazole Chlorophosphonazo Ⅰ Reagent

The spectrophotometric method is sensitive, accurate, rapid, simple, has inexpensive equipment characteristics and has a very wide applications. Spectrophotometric reagents are commonly used for the measurement of trace metal ions. In particular, azo-pyrogallol reagents are important spectrophotometric reagents because they display a high sensitivity for the determination of metal ions.As a result of this, through the use of consult massive materials, we synthesized a new spectrophotometric reagent of5-carboxylic-1,2,4-triazole Chlorophosphonazo Ⅰ (called CTACPA for short) as a matrix by using3-Amino-1,2,4-triazole-5-carboxylic acid hydrate. The molecular structure of the compounds prepared were identified by IR and1H NMR. This paper researched the reaction of CTACPA with Lanthanum(Ⅲ), Copper(Ⅱ) ions chromogenic reaction conditions, established the analysis of trace Lanthanide, Copper analysis method. Based on the discoloring reactions of Copper(Ⅱ), Iron(Ⅲ) and Vanadium(V), a linear function of the amount in a certain range was established, and the trace amounts of Copper, Iron, Vanadium analysis method was set up. The results show that CTACPA has good selectivity and a high sensitivity.The chromogenic reaction of CTACPA with La(Ⅲ) showed that CTACPA reacted with La(Ⅲ) to form a stable purple complex(2:1by mole) in the medium of HAc-NaAc with a pH of4.0. The maximum absorption wavelength was at645nm and the apparent molar absorptivity was3.79×104L·mol-1·cm-1. La(Ⅲ) concentration in the range of0.08-0.8mg/L with Beers’law. This method has been used for the direct determination of Lanthanum in hydrogenation catalyst samples of Pt-La/CNTs and Pt-La/ZrO2. The results agree well with the measured result of AAS.The chromogenic reaction of CTACPA with Cu(Ⅱ) showed that CTACPA reacted with Cu(Ⅱ) to form a stable purple complex(1:1by mole) in the medium of HAc-NaAc with a pH of4.0. The maximum absorption wavelength was at700nm and the apparent molar absorptivity was1.66×104L·mol-1·cm-1. Cu(Ⅱ) concentration was found to be in the range of0.08～0.8mg/L with Beers’law. This method has been used for the direct determination of Copper in Aluminium alloy sample and Magnesium alloy sample. The results agree well with the measured result of AAS. The oxidative fading reaction between CTACPA and hydrogen peroxide with Cu(Ⅱ) in the medium of HAc-NaAc took place at a pH of4.0. The maximum absorption wavelength was at535nm. The calibtation curve was linear and in the range of0.004～0.2μg/mL for copper. The linear regression equation was ΔA=3.0260C-7.24×10-3(C:μg/mL) with a correlation coefficient of0.9996. This method has been used for the direct determination of trace Copper in the hair and water samples. The results agree well with the measured result of AAS.The oxidative fading reaction between CTACPA and hydrogen peroxide with Fe(Ⅲ) in the medium of NH4Ac took place at a pH of7.0. The maximum absorption wavelength was at540nm. The calibration curve was linear in the range of0.02～0.2μg/mL for Iron, and the linear regression equation was ΔA=5.7027C+0.0548(C:μg/mL) with a correlation coefficient of0.9992. This method has been used for the direct determination of trace Iron in hair and flour samples. The results agree well with the measured result of AAS.The oxidative fading reaction between CTACPA and potassium bromate with V(Ⅴ) in the medium of HAc-NaAc took place at a pH of4.0. The maximum absorption wavelength was at536nm. The calibtation curve was linear in the range of0.02～0.2μg/mL for Vanadium, and the linear regression equation was ΔA=5.7027C+0.0548(C:μg/mL) with a correlation coefficient of0.9992. This method has been used for the direct determination of trace Vanadium in hair and flour samples. The results agree well with the measured result of AAS.Through the research of CTACPA, we believe that as a new chromogenic reagent, CTACPA has good selectivity and high sensitivity. Therefore it can be used for the measurement of some metal ions.