At 08:29 AM 1/23/01 -0700, you wrote: >I'm curious why dry weight is of interest unless a nitrogen analysis or other >such work is planned, and I wonder if anyone has done any analysis to see how >much of what comes off under such heat is moisture? Alan: When we started, all of the literature about bee poisoning was reported as some concentration X or dose per bee, and in court cases witnesses would say that all of the dose response studies reported how much the bee was exposed to, not what ended up in the bee. We also heard that bees varied so much, that one could never make any estimates of what the maximum or minimum amount per bee might be as a result of these dose trials. But, most beekeepers who have sustained a pesticide kill have dead bee bodies as their only evidence, and the only option is to analyze the bee bodies for residues. Again, we found that there was no standard for reporting body burden residues in the U.S. and other countries. The only consistent way to compare the results is to determine the amount of the pesticide per bee on a dry weight basis. Not all labs or studies do this, so you will find results expressed on a wet weight basis, a dry weight basis, and some unusual (to us in the U.S.) values such as mg% (that one took us some time to figure out). But, if you have an idea of the moisture content of a bee (and yes, there may be some volatiles lost, but the weight of these compared to that of water in the bee is likely to be small), the dry weight, and the wet weight - you can generate estimates of concentrations of the pesticide or contaminant per bee - even if the original study or lab did not address this issue. Obviously, these are estimates, covering a range of values - but it does put some brackets on the values. Cheers Allen Jerry J. Bromenshenk, Ph.D. Director, DOE/EPSCoR & Montana Organization for Research in Energy The University of Montana-Missoula Missoula, MT 59812-1002 E-Mail: [log in to unmask] Tel: 406-243-5648 Fax: 406-243-4184 http://www.umt.edu/biology/more http://www.umt.edu/biology/bees