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Thermo Fisher Scientific

Verify your sample with QCheck

In a QCheck analysis, your sample is compared to a known reference spectrum and the software provides a match value and a pass or fail result. QCheck is great for quickly verifying that your sample matches your internal standard.

For a more detailed walkthrough on using QCheck, see Verify Sample Composition with QCheck.

Verifying samples with QCheck

To perform a QCheck analysis, measure your sample as usual. Then, in the Spectra view, go to the Identify menu and select QCheck.

QCheck Setup

Use QCheck Setup to configure your QCheck analysis. Your saved QCheck settings will be used automatically when you select QCheck as your analysis type before measuring a sample or when you select QCheck from the Identify menu.

For more on using QCheck, see Verify Sample Composition with QCheck.

OMNIC-paradigm-qcheck-setup.png

Setting

Description

High Sensitivity

Select high sensitivity for more exact results between a sample that is very similar to the reference. You may want to deselect high sensitivity if you are measuring samples with some natural variation.

Pass/fail threshold

Set a threshold for pass or failure. Enter an integer between 0 and 100.

A correlation value of 100 indicates a perfect match.

If you de-select this option, all results will show Pass.

Maximum spectra in QCheck results

Sets the number of results shown in the results panel. For example, if you set the value to 2, only the two best matches will be shown in the results panel.

Prompt for reference

Select to choose a reference during the measurement. De-select to specify one or more reference spectra in advance. If you are planning to compare several samples to the same references, it is convenient to set them in advance to avoid having to keep selecting the same reference every time you measure a sample.

To use a compound from a library as your reference, first extract the compound so that it is available in your database.

Blank diamond ATR region (2200 - 1955)

Select to exclude data in the region from 2200 wavenumbers to 1955 wavenumbers, where diamond ATR crystals absorb radiation.

Blank CO2 region (2390 - 2240)

Select to exclude data in the region from 2390 wavenumbers to 2240 wavenumbers, where carbon dioxide absorbs radiation.

Use full spectral range

Select to use the full range in the analysis.

De-select to specify only a limited range to use for the analysis.

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