The following atomic absorption results were obtained for determinations of Zn in multivitamin tablets. All absorbance values are corrected for the appropriate reagent blank (c_Zn = 0.0 ng/mL). The mean value for the blank was 0.0000 with a standard deviation of 0.0047 absorbance units.

(a) Find the mean absorbance values for the 5.0- and 10.0-ng/mL standards and for the tablet sample. Find the standard deviations of these values.

(b) Find the least-squares best line through the points at cZn = 0.0, 5.0, and 10.0 ng/mL. Find the calibration sensitivity and the analytical sensitivity.

(c) Find the detection limit for a k value of 3. To what level of confidence does this correspond?

(d) Find the concentration of Zn in the tablet sample and the standard deviation in the concentration.

Transcribed Image Text:

CZn ng/mL A 5.0 0.0519 5.0 0.0463 5.0 0.0485 10.0 0.0980 10.0 0.1033 10.0 0.0925 Tablet sample Tablet sample Tablet sample 0.0672 0.0614 0.0661