Recent advances in the determination of calcium and its use as an internal standard in environmental samples: fundamentals and applications

Calcium is a major component of the human body and has many important functions in the environment. This review considers major developments in atomic spectrometry for the determination of calcium in environmental samples, focusing upon inductively coupled plasma – optical emission spectrometry (ICP-OES), inductively coupled plasma – mass spectrometry (ICP-MS), and laser-induced breakdown spectroscopy (LIBS). The use of calcium as an internal standard is also discussed. Major developments in instrumentation, methodology, calibration routines, and data processing are critically reviewed. Significant applications are discussed, including aerosol/atmospheric, animal, astronomical, biomonitoring, and plant samples. The focus of future work is projected to be on LIBS to achieve the goals of more rapid, stand-off (remote), and combined spectroscopic analysis with minimal sample preparation, as well as ICP-MS for high-resolution isotopic measurements and LA-ICP-MS for elemental imaging of solid samples.