Inductively coupled plasma – mass spectrometry (ICP-MS) is widely recognized as one of the most accurate and precise analytical techniques for the determination of many trace elements in a wide variety of sample types. However, analyses using a conventional instrument configuration have also been persistently challenging due to spectral interferences that can severely compromise the accuracy of reported results.

Brooks Applied Labs supports trace elements quantification using both promulgated and internally generated methods depending on the data objectives and administrative requirements of the project. We use state of the art, inductively coupled plasma mass spectrometry with various interference removal technologies, to accurately determine arsenic, selenium, iron, chromium and various other elements with previously unattainable detection limits. Current interference removal technologies supported at Brooks Applied Labs includes: dynamic reaction cell (DRC), collision reaction cell (CRC), and triple quadrupole (QQQ). The availability of the different technologies allows us to choose the most appropriate approach to support the quality and data objective of nearly any project.

Conventional ICP-MS are prone to interferences from the matrix components that form polyatomic species in the plasma (Table 1). Interference removal technologies are designed to reduce interferences and overcome many of these limitations. The end result is the elimination of false-positives and lowest detection limits for the toughest matrices.

 

Table 1. Various analytes and common interferences that affect them

Analyte

Interference

Source

Chromium (52Cr) 40Ar12C+ Carbon
Chromium (53Cr) 37Cl16O+ Chlorine
Arsenic (75As) 40Ar35Cl+, 40Ca35Cl+ Chlorine, Calcium
Selenium (78Se) 40Ar38Ar+, 38Ar40Ca+ Argon (plasma gas), Calcium
Selenium (80Se) 40Ar40Ar+, 32S16O3+, 40Ar40Ca+ Argon (plasma gas), Sulfur, Calcium
Selenium (82Se) 81Br1H+, 34S16O3+ Bromine, Sulfur
Iron (54Fe) 40Ar14N+, 37Cl16O1H+, 38Ar16O+ Nitrogen, Chlorine, Argon (plasma gas)
Iron (56Fe) 40Ar16O+, 40Ca16O+ Argon (plasma gas), Calcium
  1. S. D. Tanner, V. I. Baranov, Atomic Spectroscopy, 20, 2, 45-52, (1999)
  2. K. Kawabata Y. Kishi, and R. Thomas, Analytical Chemistry, Vol. 75, No. 9, 423A, (2003)

The analyses of samples that contain abundant amounts of particular elements, such as calcium, carbon, chlorine, magnesium, potassium, sodium, or sulfur, can dramatically further increase the formation of polyatomic ions to levels that can easily exceed even those of the analytes of interest.

Numerous elements, especially arsenic, chromium, iron, nickel, selenium, and vanadium, are known to be frequently affected by these spectral interferences, with just a few of the common polyatomic ions listed in the table below. Without an analytical technique to eliminate these interferences, costly decisions might be made based on inaccurate data.

More information about the different interference removal technologies can be found here:

  • ICP-QQQ-MS (inductively coupled plasma triple quadrupole mass spectrometry)
  • ICP-CRC-MS (inductively coupled plasma collision reaction cell mass spectrometry)
  • ICP-DRC-MS (inductively coupled plasma dynamic reaction cell mass spectrometry)

To learn more about our innovative analytical methods and how they can benefit your projects, contact us today.