Ensuring Accurate Analysis: The Role of ICP Calibration Standards

Introduction

Inductively coupled plasma (ICP) spectroscopy is a powerful analytical technique used to detect and measure elements within chemical samples. With applications spanning the biomedical, pharmaceutical, environmental, and industrial sectors, the accuracy and reliability of ICP spectroscopy are paramount. Central to maintaining this accuracy is the use of calibration standards, which ensure precise and consistent measurements.

Understanding ICP Spectroscopy

ICP spectroscopy involves the ionization of a sample by plasma, typically generated from argon gas through radio frequency energy. This technique is utilized in both inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectrometry (ICP-OES). These instruments offer several advantages over traditional methods for trace element detection, including the ability to measure multiple elements simultaneously and a broad analytical range.

The Importance of Calibration Standards

For ICP-MS and ICP-OES detectors, the signal measured correlates to the number of ions hitting the detector per second. To convert this signal into accurate concentration values, calibration standards with known element concentrations are used to create a calibration curve. This process, known as external calibration, is critical for accurate measurements.

Types of Calibration

External Calibration

    • Involves creating a calibration curve using standards with known concentrations.
    • Compound-independent calibration is used, where one chemical species of an element is calibrated using another.

Internal Standardization

    • Corrects for instrument operating condition changes and sample-specific matrix effects.
    • An internal standard, with properties similar to the analyte, is added to each sample to calculate results using the ratio of analyte to internal standard signal.

Matrix-Matching

    • Ensures samples and calibration standards are matrix-matched to avoid analytical bias.
    • Involves adding a matrix-match solution to calibration standards or using isotopic dilution in ICP-MS, where an isotopically-enriched isotope (calibration standard) is added to the sample to measure the change in isotope ratio.

Inorganic Ventures Calibration Standards

To achieve accurate ICP results, using suitable and reliable calibration standards is crucial. Inorganic Ventures, with its extensive expertise in wet chemistry and analysis, offers a comprehensive range of certified reference materials (CRMs) for ICP and ICP-MS standards. Their catalog includes single- and multi-element solutions tailored for spectroscopic instrument calibration.

ICP Standards Offered by Inorganic Ventures

  • Single Element Standards
  • Multi-Element Standards
  • Isotopic Standards
  • Cyanide Standards
  • High Purity Ionization Buffers
  • Speciation Standards
  • EPA Standards
  • Platinum Cobalt Color Standard
  • Custom Standards

Inorganic Ventures ensures all ICP standards are fully NIST-traceable and produced to exacting specifications using high-purity starting materials and strict quality assurance guidelines.

The accuracy and reliability of ICP spectroscopy hinge on proper instrument calibration using high-quality standards. By employing robust calibration techniques and standards from trusted providers like Inorganic Ventures, industries can ensure precise elemental analysis, thereby supporting critical applications in various fields.