Development of a Water Matrix Certified Reference Material for Volatile Organic Compounds Analysis in Water.

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Reference Materials

Background:

• Accurate analysis of volatile organic compounds (VOCs) in water is crucial for environmental monitoring and public health.
• Quality assurance and quality control (QA/QC) rely on certified reference materials (CRMs) for method validation and calibration.

Purpose of the Study:

• To develop and certify a water matrix certified reference material (MCRM) for 28 volatile organic compounds (VOCs).
• To ensure the homogeneity and long-term stability of the developed MCRM for reliable QA/QC applications.

Main Methods:

• A "reconstitution" approach was employed, adding a VOCs spiking methanol solution to pure water just before analysis.
• Gravimetric preparation of the VOCs spiking solution, divided into seven groups.
• Homogeneity and long-term stability were assessed using gas chromatography-mass spectrometry (GC-MS) according to ISO Guide 35.
• Certification of the MCRM was performed by a network of nine independent laboratories.

Main Results:

• The VOCs spiking solution demonstrated excellent homogeneity and was stable at room temperature for at least 15 months.
• The water MCRM for 28 VOCs was successfully certified.
• Certified values for the 28 VOCs ranged from 6.2 to 17 μg/L, with expanded uncertainties from 0.5 to 5.3 μg/L.

Conclusions:

• The developed water MCRM is suitable for QA/QC in VOCs analysis in water.
• The established homogeneity and stability support its use as a reliable reference material.
• The certified values and uncertainties provide a benchmark for accurate VOC quantification in aqueous matrices.