Question

Species of arsenic found in drinking water include AsO₃^3- (arsenite), AsO₄^3- (arsenate), (CH₃)₂AsO₂^-(dimethylarsinate), and (CH₃)AsO₃^2- (methylarsonate). Pure water containing no arsenic was spiked with 0.40 µg arsenate/L. Seven replicate determinations gave 0.35, 0.35, 0.40, 0.36, 0.39, 0.37, and 0.36 µg/L.

(a) Find the mean.
µg/L
Find the standard deviation.
µg/L
Find the mean percent recovery of the spike.
%

(b) Find the concentration detection limit.
µg/L

Answer 1

.4 0, 0 3G,0.3,0.31, omd 036/L a) Mean О. 35-40-3s-t 0.40+0.36.+ 0 . 39-+ 0.37 Subtracting tu m -0,01,-Ο.01, 0.02-, o , o.09, 0.01, o x- (-0,01). (-О.01)+(0 .02)40+@ ,03)~t(0.01)t | .0163 x1uD addud 0.4D 3x (o 0143