Worldwide there are many regulatory organizations safeguarding the environment by the issuance of health and environmental standards, such as the United States (U.S.) Environmental Protection Agency (EPA) and the European Committee for Standardization (CEN). These standards include many standardized guidelines for the analysis of hazardous environmental contaminants. The challenge for today’s laboratories is to correctly execute these guidelines, such as those described in the EPA methods, including calculating and assessing the final results. In many labs, the chromatographic results generated while executing these methods are transferred to spreadsheets in order to perform the calculations and assess the final results. This process can be time-consuming and transcription errors are a common problem. As a result, laboratories may generate results that are hard to compare, are inconsistent, and can even be misleading. In order to establish a system for compliance with the regulatory methodology, environmental laboratories develop internal guidelines, such as standard operating procedures (SOPs), for sequence creation, sample analysis, and result calculation. Mass spectrometry (MS) is becoming a more common chromatography detection technique in environmental laboratories and is also used in a wide variation of environmental methods. However, MS instruments often use specific software, without the flexibility of a chromatography data system (CDS) which forces users to learn another software package. The Thermo Scientific GC-MS has a solution for drinking water and solid waste analysis following the U.S. EPA guidelines using
one CDS, including all required calculations and assessment of the final result. This solution helps ensure that analysts follow SOPs consistently and accurately, resulting in high quality and reliable results, saving valuable time, and ensuring data integrity.
It is essential that routine environmental laboratories monitor drinking water for the presence of purgeable organic compounds. POCs have the potential to cause negative health effects when consumed. EPA Method 524.4 is used in environmental analysis labs to test water samples for volatile organic compounds (VOCs).1 It is extremely important that routine laboratories accurately detect and quantitate VOCs to ensure water is safe for the public. This method is a revised version of EPA Method 524.2 on which more details can be found here. Due to technological advances in analytical instrumentation and techniques, this method allows the analyst to modify P&T parameters and GC/MS conditions. This can result in reduced sample run time and increased laboratory throughput in a 12-hour period.
With this method, flexibility comes strict quality control (QC) requirements for EPA Method 524.4. Along with MDL and Initial Demonstration of Capability (IDC) calculations, MRL confirmation is required. The MRL is the minimum concentration that can be reported by a lab and can be very difficult to achieve as you have to determine the ±50% limits of the low-level standard in the calibration. These limits are used for low-level Calibrating Check Standards and determine if the calibration is still valid during routine analysis. In order to perform EPA Method 524.4, method acceptance criteria must be achieved. These criteria include assessing the linearity and detection limits for a wide range of compounds. The analytical method must produce consistent results and be reproducible from day today. As the sample matrix is water, it is essential that moisture is not introduced into the analytical column as this could damage the column and affect the results. The following Application note evaluation describes the use of the ISQ 7000 MS system coupled to the Atomx XYZ P&T for U.S. EPA Method 524.4.