DHA Results
The DHA Results section on the DHA tab contains information about the detected compounds and calculated results. The calculation details can be found the chapter "Appendix - Mathematical Formulas".
Chromatogram window - DHA - DHA Results
Above the table, you can see information about the signal from which the results were calculated, and also the selected norm. To obtain valid data, you must create a calibration first using Create DHA Calibration. The calibration must use the same norm as selected for displaying the Results. Otherwise, you will see one of the following warnings:
| Warning | Description |
|---|---|
| Linked calibration was not generated by DHA | The Calibration you have linked to the chromatogram was not created using the DHA Extension. Create it using the n-paraffins known sample via the Create DHA Calibration… button. |
| Norm selected for DHA Method <norm name> and DHA Calibration <norm name> do not match | Different norms are selected in DHA Results and DHA Calibration. |
| Unretained Peak Time has to be enabled in Calibration | The Retention Indexes use Log. Interpolation with Unretainded Peak option in the Calibration Options dialog in the linked Calibration is not enabled. |
| Unretained Peak Time in Chromatogram <number> and DHA Calibration <number> do not match | Your linked DHA Calibration was generated with a different Unretained Peak Time than the one set in the current DHA Method. Correct this in the DHA Settings or create a DHA Calibration again with the correct Unretained Peak Time. |
| Unretained Peak Time is non-zero | This is an informational message that appears when the Unretained Peak Time is set to a non-zero value. |
| DHA Calibration is not linked | Calibration is not linked. You will not see any results until you link a DHA Calibration. |
Retention Index of a compound. Calculated as described in the chapter "Appendix - Mathematical Formulas"
If the chromatogram contains calibrated peaks or groups, their names are shown in this column. The compound names are retrieved from the norm table (the DHA.csv file located in the CLARITY\DatFiles\Common directory) according to the selected norm, corresponding to the calculated retention indexes based on the calibration.
The hydrocarbon type of the compound retrieved from the selected norm.
Corrected Area of a specific compound in the measured chromatogram, is calculated from the chromatogram peak area multiplied by the relative response factor (more details in the chapter "Appendix - Mathematical Formulas").
% Area of the a specific compound in the measured chromatogram. The value is based on the corrected area value (this means that it is in fact based on the compound amount - more details in the chapter "Appendix - Mathematical Formulas").
% Weight of a specific compound in the measured chromatogram. The value is based on the entire sample amount. It may be corrected by the undetected compounds percentage (like water etc., determined by external methods) entered in the Undetected Compounds field. When this field is non-zero, the % Area and % Weight values are equal. Upon entering an Undetected Compounds content, the % Weight values will be recalculated accordingly (more details in the chapter "Appendix - Mathematical Formulas").
% Volume of a specific compound in the measured chromatogram. It is calculated as the (% Weight)/(Relative Density) ratio normalized to the sum of 100% (more details in the chapter "Appendix - Mathematical Formulas").
Note:
In case any of the mentioned properties (Corrected Area, % Area, % Weight, % Volume) are not calculated for a specific compound, however there is no error, the necessary calculation parameters are probably not defined in the selected norm.
A Warning may appear if the compound name is not found in the selected norm. You can match the present compound name with a compound name in the norm by clicking the Edit Link Table… button. In the displayed Link Table dialog, you can link compounds from the chromatogram with the compound names in the norm.