Chem3001: 2009-2010. Analysis of Real Samples: Problem Sheet 1. 1. You are to analyse yam for Cd by digesting the crushed yam in aqua-regia for 30 minutes, diluting the slurry to a fixed volume with deionized water, filtering the slurry without dilution and analyzing that solution by AAS. The operating range for the instrument is 0-5 ppm. What weight of yam will you use if it is expected that the concentration of Cd in the yam will be about 20 ppm? 2. To test for the efficiency of extraction you plan to spike a second sample of the yam prior to extraction with a known amount of Cd. It is recommended that you attempt to approximately double the amount of Cd in the sample through the spiking process. Given the weight of yam calculated in 1. above how much Cd do you need to add and how would you add it? 3.
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