peak symmetry

RGK over 1 year ago

How does MassHunter Qual calculate peak symmetry? You just do integration and receive data where symmetry value is calculated e.g. 1.4 . The you do system suitabiity (in Qual for e.g. European Pharmacopeia) and your symmetry is 0.67 ?? Why is that?

Can I get system suitability for Quant? There are some columns in Quant like Symmetry, SNR, FWHM, but I can't calculate Resolution etc.

Thank you

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0 howard_sanford over 1 year ago

Hello RGK ,

From what I can find, both Qual and Quant use the following formulas/definitions for symmetry depending on whether or not a particular pharmacopeia is selected. This is from the Quant Dataset manual.

Default would be used if no pharmacopeia is selected, which would be the case in Qual if system suitability is not enabled.

Regarding the columns in Quant, while some values are always calculated, others are only calculated if an outlier/limit is specified. The resolution is one such calculation, where the calculation type and limit must be specified for the Peak Resolution outlier before a value is calculated.
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0 howard_sanford over 1 year ago

Hello RGK ,

From what I can find, both Qual and Quant use the following formulas/definitions for symmetry depending on whether or not a particular pharmacopeia is selected. This is from the Quant Dataset manual.

Default would be used if no pharmacopeia is selected, which would be the case in Qual if system suitability is not enabled.

Regarding the columns in Quant, while some values are always calculated, others are only calculated if an outlier/limit is specified. The resolution is one such calculation, where the calculation type and limit must be specified for the Peak Resolution outlier before a value is calculated.
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0 RGK over 1 year ago in reply to howard_sanford

Dear Howard, thank you.

I'm working on method to analyze Agilent checkout sample 05970-60045 containing biphenyl, p-chlorodiphenyl, and methyl palmitate in isooctane (100ppb, 10ppm and 100ppm) for PQ- performance verification of my GCMS (7890A/7000). I also recently posted other question concerning this standard. And before i received the answer from Mr. Paul Salverda I thought that I might use System Suitability feature in Qual for PQ - Performance Verification (to have the analytical method that I may run every few months). I wonder if I do something wrong:

In Quant there are symmetry values (Symmetry 1) for specific ions (m/z). Then in Qual, I extracted and integrated the same ions (Symmetry 2) and after that I applied a System Suitability function and took the readings (Symmetry 3).

			after ion (m/z) extraction	after System Suitability analysis
		Quant	Qual	Qual
	Ion (m/z)	Symmetry 1	Symmetry 2	Symmetry 3
Dodecane	71	2.14	0.8	0.8
Biphenyl	154	2.28	0.5	0.5
p-chlorodiphenyl	188	2.41	0.42	0.42
Methyl Palmitate	143	1.96	0.6	0.6

Anyway, I just wanted to signalize this situation and like I said earlier, I may do something wrong which I haven't figured out yet. So, I will take a closer look at this symmetry readings.

Do you think that it is a good idea to run this standard mix as the PQ test?

Thank you again.

Robert

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