Clarity discussion forum

Calibration, ISTD and Reference peak

Dear all,

I have some doubts on how to use the aforementioned issues. In fact I'd like to build calibrations using one ISTD as internal standard and as reference peak. For that I want to divide all peak areas by the ISTD area and to divide all retention times by the ISTD retention time. In my opinion this a very safe and robust way to build a method and a calibration but so far I could only perform with success ESTD calibrations. Any help on this subject would be most welcome

Regards,

José

José Catita, PhD
Technical Manager

PARALAB,SA Equipamentos Industriais e de Laboratório
Tv. do Calvário,65
4420-392 Valbom GDM
PORTUGAL
Tel. +351 22 466 4320
Fax. +351 22 466 4321

Dear Jose,

Clarity provides tools for all the mentioned issues. In the calibration table column Peak Type any peak can marked as The peak can be marked as reference peak (Refer) or ISTD peak (ISTD) or both reference and ISTD peak (RISTD).

To have Clarity calculate the relative calibration curve it is necessary:
- to have at least one peak marked as ISTD peak (as mentioned above) with properly filled in Amount
- to fill in the ISTD Amount (in the appropriate column of the sequence table or in Single Analysis dialog)
- the calculation mode must be set to ISTD in the template method Method Setup - Calculation.

The ISTD Amount and ISTD claculation mode can be also provided later in the allready measured chromatogram (Chromatogram window - Results tab - in the Calculation and ISTD Amount fields found in the right part of the tab.

(There is a picture in the Clarity online Help, that describes these fields of the Chromatogram window -> in the help index, locate the ISTD Amount keyword and from the offered topics select "Chromatogram - Calculation - ISTD Amount")

Should you have any problem with setting it up, let me know.

with best regards

Petr Kohutek