How to calculate LOD and LOQ / How to calculate Limit Of Detection and Limit Of Quantitation ?

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chemist_isi

Күн бұрын

Пікірлер: 42

@science3722 2 жыл бұрын

Thanks for this simple explanation

@amas9797. 4 жыл бұрын

Thank you , you are really helped me to solve my home work .

@mariaignaciamezacerda9834 4 жыл бұрын

Hi. Thanks for the explanation. Can U tell us the source of the formula for LOQ and LOD? a paper or book? Thanks

@norouziparviz8085 5 жыл бұрын

Hi, there is a problem here, when LOQ is 6.9, is it possible to measure concentration 2.6? (which is the first point of the calibration curve ( or linear range)).

@chemist_isi 5 жыл бұрын

That is why, after lab analysis, we must do Quality control of the analytical method.

@قائدبكرعلي Жыл бұрын

Thank you

@marvincearaneta9389 4 жыл бұрын

Hii! Thanks for the help. Can I ask for the source of the formulas like probably a journal? Thankiess

@qiuyinrui9305 3 жыл бұрын

but what if we change to another series of standard points - it would be another value of DL and DQ umh? even just simply add or minus points can lead to a change of N, like one comment referred - is there any notice or rules we usually choose what range of concentrations as our data sources?

@jeanniedevereaux5857 3 жыл бұрын

Thank you very much

@gumball665 3 жыл бұрын

thank uu

@splekort 3 жыл бұрын

Hello. Your estimation included the intercept and the slope, so why you did not use 2 degrees of freedom? Or when should 2 degrees of freedom be used?

@dr.brijdablain9003 3 жыл бұрын

Very informative, can you help us to calculate all this using ORIGIN

@jiahuizhao9965 6 жыл бұрын

Excuse me, I have a question about the SD of intercept and SE of intercept, why SD =SE*√N.Shouldn't we calculate LOD/LOQ directly by using the results of regression? Hope for your reply, thank you so much.

@jiahuizhao9965 6 жыл бұрын

Yeah, I'm the first time to hear about this one.Do you usually use GC/HPLC?

@chemist_isi 6 жыл бұрын

Thanks for the question. Yes, we don't need SD for the calculation LOD and LOQ. But when we are preparing QC validation of the analytical method, at that time we need SD. It is for information only. You can check the video, kzbin.info/www/bejne/rIK5dIBvm8eSp5o

@chemist_isi 6 жыл бұрын

Ye of course I am using GC and HPLC systems :)

@malakmohamed4346 5 жыл бұрын

thank you for the information

@seanlim5144 4 жыл бұрын

you save my day

@etcbs4113 2 жыл бұрын

Is R2 could be equal 1?

@kirenkoalex7668 5 жыл бұрын

What for do we use square root from N? In this case the higher is N the higher LOD value is too. But the more points (levels) we have the more precise data and the lower LOD must be.

@iosonosenzanome 3 ай бұрын

because from SE to SD you have to multiply for this factor

@nassimalijani8269 Жыл бұрын

Hi. Thank you so much. May I have that word file containing formula for calculations please?

@hassanzia4139 2 жыл бұрын

Can you guide how LoD and LoQ will be calculated for metals and metal oxides by Fluorescence

@헤헹-f1j 5 жыл бұрын

Thank u so much!!

@aishwaryasingh7075 5 жыл бұрын

what will be unit for LOD and LOQ

@chemist_isi 5 жыл бұрын

It depends on the method. Which unit you are using, it will be the same.

@LucianLusilver 4 жыл бұрын

If we have two analytes in a mixture, does that mean we do two separate calculations of these? Sorry if my question sounds redundant.

@punchymuffin6402 3 жыл бұрын

The LOD and LOQ you calculated here will have the same units as values in the x column, right? If your concentration units are ng/mL, then are the LOD and LOQ calculated in ng/mL too? You don't have to plug the values obtained for LOD and LOQ back into the equation for the line and solve for x do you?