ICP-MS
Inductively coupled plasma mass spectrometry detects trace elements at very low levels.
Practise Analytical, Lab & Spectroscopy All Analytical, Lab & Spectroscopy topics
Inductively coupled plasma mass spectrometry detects trace elements at very low levels.
Practise Analytical, Lab & Spectroscopy All Analytical, Lab & Spectroscopy topics
Inductively coupled plasma mass spectrometry combines an argon plasma at 6000 to 10000 K with a mass spectrometer to detect trace and ultratrace elements. The sample is nebulized into the plasma, where it is desolvated, atomized and ionized almost completely, and the resulting ions are extracted into a mass analyser that separates them by m/z. Because nearly every element can be ionized in the plasma, the technique reaches detection limits in the parts per trillion range for many elements and can measure isotope ratios. Interferences from polyatomic ions formed in the plasma must be corrected using collision cells or high resolution. ICP-MS is widely used in environmental monitoring, geochemistry and clinical analysis.
Key ideas: Samples are usually acidified (1 to 2 percent nitric acid) and digested to remove organics. Internal standards such as indium or rhenium correct drift. Quantify with a calibration curve spanning ppt to ppb. Isotope dilution gives the highest accuracy. The argon plasma gives an ionization efficiency near 100 percent for most elements with ionization energy below 8 eV. Spectral overlaps include 40Ar16O on 56Fe.
Common mistakes and connections: Students assume that ICP-MS gives species information, but it only reports the total element, so speciation (arsenite versus arsenate) needs HPLC coupling. High dissolved solids clog cones and suppress the signal, so samples are diluted. Contamination from reagents and glassware matters at ppt levels. Related to mass spectrometry, isotopes and atomic emission.
Lead appears in ICP-MS as four isotope peaks at m/z 204, 206, 207 and 208, with 208Pb the most abundant at about 52 percent. The interactive lesson shows this as a live animation or chart.
Trace uranium and lead in seawater are determined by ICP-MS at nanogram-per-litre levels.
Inductively coupled plasma mass spectrometry detects trace elements at very low levels.
ICP-MS is a advanced topic in Analytical, Lab & Spectroscopy. It builds on beginner and intermediate topics, so review those first if needed.
Study these earlier topics in Analytical, Lab & Spectroscopy first: MRI, Atomic Absorption Spectroscopy, Flame Photometry.
The next topics in Analytical, Lab & Spectroscopy are X-ray Crystallography and Electron Microscopy.
Yes. The interactive lesson includes a self-check question on ICP-MS, and the Analytical, Lab & Spectroscopy quiz draws on every topic in this area.
ICP-MS is topic 53 of 99 in Analytical, Lab & Spectroscopy.