Patent ID: 7153698
Filing Date: 2006-12-26
Classification: G01N,Y10T

Abstract:
1. A method of field sample collection for the detection of arsenic species As(III), As(V) monomethylarsinate (MMA), and dimethylarsinate (DMA) in drinking water which comprises: (a) providing three separate solid-phase extraction columns for a serial extraction of the drinking water in the field wherein (1) a first of the columns which is a cation exchange column comprising a first medium for ion exchanging which removes interfering cation ions in the water from the As(V), MMA, DMA, and As(III) in the water; (2) a second of the columns which is a cation exchange column comprising a second medium at a pH of about 1.0 to 1.5 for ion exchanging which removes the DMA in the water from the As(V), MMA, and As(III) in the water; and (3) a third of the columns which is an exchange/sorption column comprising a dioctyltin dichloride coated medium at a pH of 2.5 to 3.5 which removes the As(V) and MMA from the water while the As(III) remains in the water; and (b) serially introducing the water into the first, second, and third columns, and collecting a first effluent from the third column containing the As(III).