Were noted. One sample (ID13677) for which less than 300 l was available was made up to 300 l with 50 mM ammonium bicarbonate, pH 8.0. The plate was then capped and mixed for 10 min at room temperature. After mixing, all samples were transferred to the SLE plate, loaded and incubated for 5 min at room temperature. The samples were then eluted with 900 l 75:25 hexane/ethyl acetate. The eluate was d