Metrohm has revealed the advantages of ion chromatography in the determination of lanthanides.
Lanthanides are of increasing technological importance.
However, the techniques commonly used to determine them require equipment well beyond the means of small budgets.
Ion chromatography applying non-suppressed conductivity or UV/VIS detection is a straightforward, less expensive alternative.
Lanthanides are commonly determined by atomic absorption spectroscopy, X-ray fluorescence, inductively coupled plasma-mass spectroscopy (ICP-MS) or inductively coupled plasma-atomic emission spectroscopy (ICP-AES).
Sophisticated as they are, these techniques come with high costs of instrumentation and require highly skilled operators.
The determination of trace-levels of lanthanides by ion chromatography is achieved by using either direct non-suppressed conductivity detection or UV/VIS detection at 655nm after post-column reaction (PCR) with arsenazo III.
Conductivity detection under isocratic conditions results in overall analysis times of approximately 70mins.
For faster analysis Metrohm suggests the determination of lanthanides via gradient elution and subsequent spectrophotometric detection of the arsenazo III-lanthanide(III) complexes, which can be performed within just 22mins.
Besides the short analysis time, UV/VIS detection excels by its selectivity and sensitivity and does not suffer from interferences by ever-present impurities such as iron(III) or other transition metals.
