In this second part of the series, the focus will be on the analysis of, especially challenging samples.
Throughput is essential when labs need to measure a number of samples with time constraints. Also, operating costs must be taken into consideration if challenging samples are affecting the results of the analysis.
Let’s dig more into this topic!
Challenge: Analysis of Challenging Samples
Sulfuric sediments or fly ashes are challenging for the sample clean-up for dioxin analysis. Squalene, a natural organic compound originally found in oil or plant sources, used in cosmetic or dermatological products, is a common challenging sample type.
These are just a few examples of samples which can present challenges for the analysis. No matter how good the sample clean-up is, your final extract always contains a certain amount of matrix. This means that the performance of any analytical instruments might be affected when analyzing the samples for dioxin or other POPs quantifications, with results that do not meet labs expectations or regulatory requirements. Clearly, a failed determination has a negative impact on the time and cost of any lab, which might require analysis to be redone or even to repeat the sample preparation process.
Solution: How to Successfully Analyze Challenging Samples
The analyses performed with the Thermo Scientific™ DFS™ Magnetic Sector GC-HRMS are supported by the Thermo Scientific™ DFS™ Software Package. The DFS Software Package includes automated features supporting full compliant routine quantifications of POPs, with the automation required to meet your lab’s needs.
The new DFS Software Package features:
Thermo Scientific™ DFS SmartTune™ Operating Software which manages the instrument’s everyday tasks, from instrument settings optimization to method development for routine dioxin quantifications.
Thermo Scientific™ DFS TargetQuan™ Data Evaluation Software enables the quantification of dioxins and other POPs, according to isotope dilution requirements, and provides easy-to-use features for calculations required by official regulations for full transparency of reporting.
The Thermo Scientific™ DFS™ Magnetic Sector GC-HRMS, the DFS SmartTune Operating Software offers, alongside the Default MID Analysis Mode (which continues to be the default mode), now includes a second optional MID analysis mode: the SmartMID feature. This mode helps solve the issue of analyzing challenging samples and can reduce the negative effects of complex matrices.
In the next part of the post, we will see how it works.
How: Use the Smart MID Feature in the DFS SmartTune Operating Software
To explain this feature, we have dedicated how-to videos on the DFS SmartTune Operating Software where you can also see how it is applied in the software. Watch the video or read more here.
On the DFS Magnetic Sector, the automated real-time calibration, which requires the determination of starting parameters based on the reference gas (introduced by a gas inlet system), is based on known ion masses of a reference gas. Their determination requires an identification of the reference mass, known as lock mass. To identify the lock mass, a certain mass range section is scanned around the theoretical mass position of the lock mass.
When highly abundant matrix ions appear within this lock mass scan, two signals are detected. In addition to the correct lock mass ion, the interference ion is detected, which can be misinterpreted as reference mass and affect the overall calibration.
In the standard approach, the calibration is carried out during the analysis, when the matrix is already in the ion source. With the Smart MID Feature, all parameters for the calibration are determined before the analysis when no sample is present. This allows you to narrow the lock mass scan, which ensures the correct calibration by excluding potential matrix interference signals.
Are you also performing analysis of challenging samples? Share your experience in the comments.
For dioxin and POPs analysis, download the new resource guide containing information on the history of POPs, the implications of their early occurrence, and today’s analytical testing methods for their accurate determination in chemical laboratories as an introduction to this global issue.
If you want to know more about POPs in food take a look at the brochure.