Colorimetric titration of Arsenite

Your company is developing cheaper methods for determining the amount of arsenic in water supplies. A new chemical, Red-K9, is a red material which bonds to arsenite according to the following reaction: AsO2- + Red-K9 ---> AsO2-Red-K9-, giving a colorless product.

In order to test the method, you are asked to determine the amount of As in the water sample. (Please use three significant figures in all your results.)