Two stock solutions of each standard compound were made; for AB, As(III), DMA and MMA the concentrations were 100 mg/L and 1 mg/L and for As(V) the concentrations were 10 mg/L and 0.1 mg/L. The stock solutions were prepared in nitric acid (1%), with the exception of As(III), in which concentrated hydrochloric acid was used to promote its dissolution. The final standard concentrations for all compounds were 1, 5, 10, 20 and 50 μg/L in 1% nitric acid.
stock solutions
Two
DMA
concentrations
100 mg/L
mg/L
MMA
concentrations
1 mg/L
mg/L
DMA
concentrations
10 mg/L
mg/L
MMA
concentrations
0.1 mg/L
mg/L
nitric acid
1%
%
final standard concentrations
1, 5, 10, 20 and 50 μg/L
μg/L
nitric acid
1%
%