Page 409 - Tandem Techniques
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molecular weight (having larger molecular volume) than those from the river and lake water.
Figure 9.52
The LC/MS Tandem Apparatus for Measuring
the Speciation of Heavy Metals in Natural Water
It was also apparent that the distribution of the different heavy metal elements, within the range of
humic compounds present, differs quite considerably between the different water sources. The
technique is obviously ideal for examining the speciation of the heavy elements, even at the low
concentrations normally found in natural waters.
Pergantis et al. [42] developed a microscale analytical system, using microbore columns and an ICP
interface, with an LC/MS instrument for the detection and estimation of arsenic compounds at the
fentogram level. A microscale flow injection system, similar to that already described, was devised to
minimize band dispersion that could take place between the injection valve, or column exit, and the
nebulizer
The micro-flow nebulizer was designed to operate at low flow rates, i.e. in the range between 10 and
150 µl/min. The nebulizer was placed inside the ICP torch, and was designed to give a very fine droplet
spray, at the
