(arsenate), (CH3)2/ (methylarsonate). Pure water containing no arsenic was spiked with 0.40 µg arsenate/L. Seven replicate determinations gave 0.39, 0.40, 0.38, 0.41, 0.36, 0.35, and 0.39 µg/L (J. A. Day, M. Montes-Bayón, A. P. Vonderheide, and J. A. Caruso, Anal. Bioanal. Chem. 2002, 373, 664). Find the mean percent recovery of the spike and the concentration detection limit. 5-16. Standard addition. Vitamin C was measured by an electrochemical method in a 50.0-mL sample of lemon juice. A detector signal of 2.02 µA was observed. A standard addi- tion of 1.00 mL of 29.4 mM vitamin C increased the signal to 3.79 µA. Find the concentration of vitamin C in the juice. 5-17. Standard addition. Analyte in an unknown gave a signal of 10.0 mV. When 1.00 mL of 0.050 0 M standard was added to 100.0 mL of unknown, the signal increased to 14.0 mV. Find the concentration of the original unknown. 5-18. Standard addition graph. Tooth enamel consists mainly

(arsenate), (CH3)2/ (methylarsonate). Pure water containing no arsenic was spiked with 0.40 µg arsenate/L. Seven replicate determinations gave 0.39, 0.40, 0.38, 0.41, 0.36, 0.35, and 0.39 µg/L (J. A. Day, M. Montes-Bayón, A. P. Vonderheide, and J. A. Caruso, Anal. Bioanal. Chem. 2002, 373, 664). Find the mean percent recovery of the spike and the concentration detection limit. 5-16. Standard addition. Vitamin C was measured by an electrochemical method in a 50.0-mL sample of lemon juice. A detector signal of 2.02 µA was observed. A standard addi- tion of 1.00 mL of 29.4 mM vitamin C increased the signal to 3.79 µA. Find the concentration of vitamin C in the juice. 5-17. Standard addition. Analyte in an unknown gave a signal of 10.0 mV. When 1.00 mL of 0.050 0 M standard was added to 100.0 mL of unknown, the signal increased to 14.0 mV. Find the concentration of the original unknown. 5-18. Standard addition graph. Tooth enamel consists mainly

EBK A SMALL SCALE APPROACH TO ORGANIC L

4th Edition

ISBN:9781305446021

Author:Lampman

Publisher:Lampman

Chapter88: Column Chromatography

Section: Chapter Questions

Problem 5P

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