Abstract: A microtiter reaction system (15), comprising, a support rack (16) having an array of reaction wells (18) disposed therein, each reaction well (18) having an open top end (30) and a closed bottom end (32); a plurality of generally funnel shaped reactor caps (20) with each of reactor cap (20) being received into open top end (30) of each reaction well (18); a porous gas-permeable layer (22) positioned over support rack (16), gas-permeable layer(22) having an array of holes (23) therein with each hole (23) being positioned over open top end (30) of each of the plurality of reaction wells (18); gasket (24) positioned over porous gas-permeable layer (22); and a top cover (26) positioned over gasket (22).

Abstract: Single pass methods and systems for measuring the total masses of individual compounds present in fluid samples in real time, and particularly for fluid samples prepared in microtiter plate format are provided. Individual compounds are isolated by fluid separation column (14). Portions of the individual compounds isolated by column (14) are analyzed by mass spectrometer (16), which determines their concentration on the basis of their molecular weights, and an evaporative light scattering detector (24), (which determines the total masses of each of the isolated compounds passing therethrough). Total collected masses of the individual compounds are calculated by determining the amount and portion of the isolated compounds diverted into evaporative light scattering detector (24) during a period of fraction collection.