One of the advantages of ICP-MSICP-QQQ as a chromatography detector is that ICP-MSICP-QQQ is a very good element-specific detector. In the future, this technique will be very important for the analysis of environment samples and biochemical samples.
Chromatography is also a very good technique to separate the sample matrix from the analytes of interest. There are three types of chromatography that can be used with ICP-MSICP-QQQ: ion chromatography (IC), liquid chromatography (LC) and capillary electrophoresis (CE).
Since most elements form cations or anions in solution, IC is a very good technique to use with ICP-MSICP-QQQ. There are two types of columns, cation exchange and anion exchange.
Basically, the IC effluent conditions can be directly applied to ICP-MSICP-QQQ, because the normal eluent flow rate for IC is about 1 mL/min which is acceptable for the ICP-MSICP-QQQ. However, some eluents cause matrix suppression or clogging at the tip of the nebulizer and the interfaces cones.
The following separations have been performed using IC-ICP-MSICP-QQQ and published:
The application of LC to ICP-MSICP-QQQ is more difficult than for IC, because the LC eluent is not always suitable for ICP-MSICP-QQQ. Higher concentrations of methanol or acetonitrile can not be analyzed with the normal sample introduction system and phosphoric acid buffers are hard to introduce into the ICP-MSICP-QQQ.
CE shows remarkable separation capability. However, the flow rate is too small for ICP-MSICP-QQQ. The typical sample uptake rate of the Agilent ICP-MS is 400 µL/min, and about 2 % of the sample actually goes into the plasma (10 µL/min). On the other hand, the typical flow rate of CE is 10 nL/min which is less than 1/10000 of the normal required flow rate of ICP-MSICP-QQQ. Therefore, the additional eluent flow is required. Consequently, the detection limit of CE-ICP-MSICP-QQQ becomes worse, around the ppb level at the best, similar to the detection limit of CE itself.