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 pushloop liquid sampling method is an improvement in the method of introducing liquid samples into test equipment (such as for liquid chromotography) via a six port valve. The method involves pulling the sample completely past the sample loop in the six port valve and then pushing the desired amount of sample back into the sample loop.