You might want to post this in the Life Sciences section, as it is more appropriate there, but let's give it a shot anyway.
Not sure about the nutrient content, but I found a few web sites with care tips, as I assume you will have to grow these for your project.
http://www.rochestergardening.com/bulbs/amrylcar.html
http://www.rnews.com/Story_2004.cfm?ID= ... ategory=10
Try doing a google search on, "Plant nutrients". I came up with this web site which seems helpful in a general sense, though not specifically for amaryllis.
http://www.agr.state.nc.us/cyber/kidswr ... trient.htm
http://www.cartage.org.lb/en/themes/Sci ... lPlant.htm
http://en.wikipedia.org/wiki/Plant_nutrition
As far as what nutrients are taken up by the plant, the only way that comes to mind offhand to measure them would be to add a known amount of nutrients to the soil before the seeds are planted, let the plant grow, and then measure the amount of nutrients left in the soil.
I'm sure there must be a way of directly analyzing the plant, but I'm not precisely sure how.
If there is a local extension office of the local agriculture department in your county, I would give them a call and ask them this exact question. They may have some good advice for you. Another thought is the Agriculture Department of a large state university in your area. Schools like Ohio State University, Illinois State University, Kansas State University, to name a few come to mind. The US Department of Agriculture is another thought, although with bigger beauracracies come bigger challenges to get useful information.
Good luck, and again you might want to post this on the Life Siences Forum to have a greater chance of getting experts in horticulture.