Direct chromium determination of cross linking agent in water from oilfield by spectrophotometry

Chromium(III) in cross linking agent of water from oilfield was oxidized to Chromium(VI) by oxidant ammonium persulfate,and chromium was determined with 1,5-diphenylcarbohydrazide spectrophotometry method.Then testing conditions of this method were detail investigated.The experimental results showed that recovery of this approach was larger than 93 %,and its average precision expressed with RSD was 3.9 %.The optimum amount of oxidant was 0.4 g for 2 mL-3mL water.From application test for water from ShengLi oilfield and result comparisons with AAS,this approach was proved to be very useful for chromium determination of cross linking agent in water from oilfield.