In GC analyses where a sample consists of a wide boiling range of components, and where their prior separation is either difficult or troublesome, injection will introduce the low volatility components into the chromatographic column. If the target solutes are those that are eluted quickly, considerable time must be spent waiting for the high boiling point components to be eluted before the next analysis can be commenced. In MDGC, it is possible to reverse the flow in the pre-column (refer to column 1 in Figure 1) to back-flush the heavy constituents out of the column and vent them through the split vent line. This can be completed whilst the higher volatility components are being separated on the second column. This flow switching will be commenced when the desired solutes have passed the midpoint valve between the two columns (back-flushing is the oldest form of MDGC and has been employed since the earliest days of GC). Back-flushing can likewise be easily incorporated into other coupled separation systems such as MDHPLC.

Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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