Abstract: A sample preparation method and apparatus is provided which is capable of automatic operation over a broad range with improved accuracy and precision, and which is capable of sampling with improved accuracy and flushing without operator intervention. A pair of syringes are used to measure large and small volumes of components, respectively, and can be operated automatically using a processor to prepare samples. Further, the method and apparatus incorporate a solvent selector valve which permits various solvents to be selected as required to prepare a particular sample. Automatic flushing of the apparatus is also provided after the preparation of each sample.

Abstract: A degassing system is provided and includes a module for conditioning a liquid to be analyzed. The module includes a container holding a liquid, a degassing chamber, and a holder for the liquid container mounted on top of the degassing chamber. The holder provides stability to the module and contains any liquid spills. In another embodiment, the system includes an autosampler in conjunction with a degassing unit which includes a degassing chamber, a vacuum pump, and tubing for conducting liquid through the degassing chamber, which tubing is permeable to gases in the liquid.

Abstract: An apparatus for effective vacuum degassing of a liquid is provided for liquid chromatography applications. The liquid to be degassed is heated in the vacuum chamber by a radiator of electromagnetic energy, in one embodiment, or is heated before it enters the vacuum chamber. The liquid may also be agitated while in the vacuum chamber. In a preferred form, the vacuum degassing unit includes a vacuum chamber including a vacuum pump for creating a vacuum therein, a source of liquid, and gas permeable tubing for conducting the liquid through said vacuum chamber. The tubing includes first and second larger diameter blocks having at least one hole therein interconnected by at least one length of small diameter tube to form a leak-tight seal therewith.

Abstract: The conventional computer program in the microcontroller of an ink jet printer-plotter is modified so as to plot a line of constant average dot density along its length, regardless of the orientation of various segments making up the plotted line. This modification provides the benefit of consistent line density for all plotted lines.