Why do we use HPLC-ICP-MS?

Most common methods to quantitate Methylmercury

1) GC-ECD (Gas-Chromatography coupled to Electron Capture Detector)
2) HPLC coupled to Hg detector (fluorescence, photometry, cold vapour atomic absorption and fluoresence spectroscopy).

In this case, why was HPLC-ICP-MS (HPLC coupled to inductively-coupled plasma mass spectrometry) used instead of GC-ECD?



Disadvantages of GC-ECD

1) High limit of detection of 10ng/L despite its long and complicated procedure

2) Low selectivity; Not specific to any element

3) Subjected to interferences, which can result in false positive results or low recoveries

Advantages of HPLC-ICP-MS

1) Compound Independent Calibration

Argon plasma is able to decompose and ionize an element regardless of its chemical structure. This independence of signal to original structure is known as compound independence, and allows the construction of a calibration graph based on the concentration.

2) Low limit of detection

3) Simple sample preparation

4) High sensitivity and selectivity

5) Stationary phase and mobile phase can be adjusted to suit the separation required

6) Sample extracts are directly injected into the system - reduced costs