4 - (5-chloro-2-pyridylazo) - 1,3-phenylenediamine is a chemical substance. The chemical formula is c11h10cln5. It is a 4 5 chloro 2 pyridylazo 1 3 phenylenediamine indicator and an organic intermediate. 4 5 chloro 2 pyridylazo 1 3 phenylenediamine test cobalt and 4 5 chloro 2 pyridylazo 1 3 phenylenediamine regeat cadmium are detected by colorimetric analysis.
The phase separation conditions of TritonX-100 for cobalt-4 - (5-chloro-2-pyridylazo) - 1,3-diaminobenzene (5-cl-padab) complex at pH 4 In the medium of 0 ~ 6.0, the micelle solution was heated to 92 ± 1 ℃ for 40 min, and the complex was enriched by Triton X-100 phase The absorbance of the enrichment solution was measured at 575 nm, and the cobalt content was 0 ~ 4 μ Beer's law is obeyed in the range of g / 5ml, and h can be added to Triton X-100 phase separation solution_ 2SO_ 4 elimination The proposed method is sensitive, simple and has been applied to the direct determination of Trace Cobalt in human hair and tap water without separation.
A method for synthesizing 4- ( 5-chloro-2-pyridylazo ) -1,3-phenylenediamine is characterized in that 2-amino-5-chloropyridine is added to an ethanol solution of sodium amide, and the mixture is ripened after addition ; drop isoamyl nitrite in the reaction solution, and ripen after drop ; the reaction solution was cooled and filtered to obtain diazonium salt, and then washed with ethyl acetate. The diazonium salt was added to ethanol, and then the mixture of m-phenylenediamine hydrochloride, sodium acetate and water was added drop by drop, and the red crystal was obtained. The red crystal is cooled and filtered, and the filter cake is suspended and washed with water. The suspended filter cake is dissolved in ethanol, filtered and concentrated, and then treated with potassium hydroxide solution. The solid obtained by filtration is finally suspended and washed with hot water to obtain high purity product.