• John Goodwin

Big toys....

So, since Christmas I have been lucky enough to learn to drive a high-performance liquid chromatograph (HPLC), coupled to a photo-diode array (PDA) and a mass spectrometer (MS) to analyse what is in my red clover samples.

Very briefly, we dissolve the compounds of interest in my red clover samples in alcohol, then stick it to resin beads at extremely high pressure (4,000 psi or thereabouts). Then, over an hour or so, we selectively wash the compounds off the beads, starting with 100% water and no alcohol, and finishing with 100% alcohol and no water.

The absorbance of ultraviolet light is measured in the washings, which tells us how much of any one compound is coming off the beads at a particular time. This gives us the graph shown here, each peak is a separate compound, and the size of the peak tells us how much of it there is.

Once measured, the washings go on to the mass spectrometer, which bombs them with electric current and breaks complex molecules into simpler ions. These simpler ions are measured by their mass:charge ratio, telling us what compound each peak represents.

Some really interesting results here ... there are lots of differences in composition between varieties of red clover. Each compound has different uses so it is exciting and useful information.......

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