Visiprep^™ Solid Phase Extraction Vacuum Manifolds andaccessories automate the preparation and cleanup of laboratory liquid samplesby solid phase extraction. Used with a vacuum pump, a Visiprep™ manifold canextract up to 12 or up to 24 samples simultaneously, significantly increasingsample throughput while decreasing sample preparation hands-on time, relativeto liquid-liquid extraction methods. Visiprep^™ vacuum manifolds feature avacuum bleed valve and a stand-alone coverto provide you with precise flow control and safe, easy use.With our flow control valves you can precisely manipulate flow through eachtube by rotating the individual screw-valves built into the cover. Our recentlyoptimized standard manifolds are suitable for SPE methods in the PFAS testingarea. All crucial components that contain PFAS (e.g. PTFE) are substituted byPFAS free alternatives like e.g ultra-high molecular weight Polyethylene (UHMWPE) or stainless steel (needle guides). These ensure low PFAS backgroundcontamination during the SPE process. The glass basin will not dissolve, fog,or discolor when exposed to powerful solvents. The manifold rack accommodatesautosampler or small scintillation vials, 10 mm or 16 mm test tubes, or 1, 2, 5or 10 mL volumetric flasks. An optional plate fits up to ten 20 mLscintillation vials in the 12-port model. The vacuum bleed valve improves control of the vacuum level andensures more secure closure of the valve. This screw-type valve is fitted withan ultra-high molecular weight polyethylene cone shaped seal (now PTFE-free).Tightening the screw ensures a complete seal with no leakage at the valve.Loosening the screw breaks the seal, allowing immediate vacuum release to stopextractions or to lift the manifold cover. Four 2" legs enable you tostand the cover on a work surface with the SPE tubes maintaining their uprightpositions. This prevents solvent guides from resting on the work surface andbecoming damaged or contaminated. Drying attachment on themanifold is sold separately, it installs in minutes and can be used with anyinert gas. The drying attachment also is useful for concentrating recoveredsamples. Gas flow to each tube can be independently adjusted.