Validation of analysis of XXXX in water samples using Wagtech Digital Arsenator.

@entity1 @entity3494
Groundwater, the only source of potable water for millions of @entity1 in Bangladesh during dry season, is often contaminated with @entity3494 (As) above the allowable drinking water limit of 50  g/L. Testing well water--with @entity3494 field test kits (FTKs)--and switching to safe-wells can effectively reduce exposure to As. FTKs are low cost, provide fast results, and are commercially available. There are between 10 and 11 million shallow tubewells in Bangladesh. Approximately, 5 million have been tested using FTKs. FTKs with color comparator rely on visual identification for generating qualitative results, which may not be highly reliable at the lower range because @entity1 eyes have low sensitivity in this range and sensitivity varies from @entity1 to @entity1 . The Wagtech Digital Arsenator does not suffer from this limitation and should, in theory, be able to generate quantitative, accurate, and reliable results. The instrument has a linear range of 0-100  g/L, an accuracy of    20% for the 50  g/L quality control standards, and a detection limit of about 4.4  g/L. All Arsenators employed in this investigation also displayed high bias for 50  g/L @entity3494 standard and were calibrated in order to improve measurement accuracy and reliability. Analyses of 179 raw and 92 treated well waters in the field and in two analytical laboratories were found to be highly correlated with the Spearman rank correlation coefficient of >=  0.800, indicating that Arsenator results are perhaps nearly as accurate and reliable as those from analytical laboratories.
