Vacuum manifold system

Figure 6.39 Parallel extraction of 96 samples with an Empore 96 individual disk SPE plate (A) and vacuum manifold system, including an acrylic vacuum manifold top (.B), a polypropylene deep-well collection plate (C), two shims (D) for height adjustment of the collection plate, and a Delrin vacuum manifold (E) bottom. (Reprinted with permission from Simpson et al., 1998. Copyright 1998 John Wiley Sons.)...

This transfer is best done on a vacuum manifold system equipped with a manometer. The trap and a stainless steel cylinder of 100-300 ni. capacity are attached via vacuum tubing to the manifold system, cooled in liquid nitrogen baths, and evacuated to 0.5-1 mm. The system is closed, the trap is removed from its cold bath and is slowly thawed. The volatile material in the trap is transferred to and condensed in the cylinder at such a rate that no positive pressure builds up in the closed system. 

Reactions were carried out in a vacuum manifold system, which enabled the formation and carbonation of the organomelallics to be conducted under conditions that excluded moisture mixture and air [50],... 

Figure 8.6 Schematic of a commercially available vacuum manifold system used in solid-phase extraction.

Vacuum manifold system, 51,56 Vanadium oxyacetylacetonate, 50,56 N-Vinylpyrrolidone, cyanation,50,54... 

Reversed-phase Cig chromatography column. Keystone Scientific Betasil, 100 x 2.0-mm i.d., 5-pm particle size, 100 A, Part No. 105-701-2-CPF TSQ 7000 LC/MS/MS system with electrospray ionization (ESI) or atmospheric pressure chemical ionization (APCI) interface and gradient high-performance liquid chromatography (HPLC) unit, or equivalent Vacuum manifold for use with SPE cartridges (Varian Vac Elut 10 or equivalent)... 

In the last several years, on-line extraction systems have become a popular way to deal with the analysis of large numbers of water samples. Vacuum manifolds and computerized SPE stations were all considered to be off-line systems, i.e., the tubes had to be placed in the system rack and the sample eluate collected in a test-tube or other appropriate vessel. Then, the eluted sample had to be collected and the extract concentrated and eventually transferred to an autosampler vial for instrumental analyses. Robotics systems were designed to aid in these steps of sample preparation, but some manual sample manipulation was still required. Operation and programming of the robotic system could be cumbersome and time consuming when changing methods. 

If visual inspection of the most suspect joints or stopcocks fails to reveal the leak, a systematic isolation of parts of the vacuum system is in order. For a vacuum line of conventional design (e.g., a line approximating that in Fig. 5.2), it is generally best to turn off all stopcocks which interconnect the various parts of the vacuum system. As a result, the high-vacuum manifold is isolated from the pumps and the rest of the line, and it is checked by determining if there is a steady pressure rise in that section. If this section appears to be intact, but it... 

A manifold system connected to a vacuum line and a nitrogen line was used. 

The degree of automations has literally revolutionized nucleic acid purification. The core of these systems are the automated liquid-handling workstations that involve the movement of multiple probes in Cartesian axes (x, y, z) over a deck configured with lab ware, such as microplates, tube racks, solvent reservoirs, washbowls, and disposable tips. They have the ability of aspirating and dispensing solvents from a source to a destination. Devices such as vacuum manifolds, heating blocks, and shakers have also been modified to handle 96-well (or more) plates. The multiprobe liquid handlers have a variable tip spacing that allows them to expand their tip-to-... 

---