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

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

[@mariaignaciamezacerda9834]

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

[@marvincearaneta9389]

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

[@kirenkoalex7668]

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]

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

[@qiuyinrui9305]

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?

[@norouziparviz8085]

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]

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

[@splekort]

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]

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

[@nassimalijani8269]

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

[@jiahuizhao9965]

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]

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

[@chemist_isi]

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,
th-cam.com/video/vQVCM9fb_q8/w-d-xo.html

[@chemist_isi]

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

[@etcbs4113]

Is R2 could be equal 1?

[@science3722]

Thanks for this simple explanation

[@punchymuffin6402]

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?

[@hassanzia4139]

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

[@amas9797.]

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

[@LucianLusilver]

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

[@aishwaryasingh7075]

what will be unit for LOD and LOQ

[@chemist_isi]

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

[@toasterspoon5000]

hello, I was hoping if you can add audio of a walk through.

[@قائدبكرعلي]

Thank you

[@niravghinaiya2491]

what is unit of LOD??

[@josuereyesarcos5575]

you define it

[@jeanniedevereaux5857]

Thank you very much

[@krish_krish354]

Show slowly the function u click. Not able to follow for beginners.

[@chemist_isi]

Ok

[@chemist_isi]

Check this video
th-cam.com/video/gTAk8hL9D-A/w-d-xo.html

[@malakmohamed4346]

thank you for the information

[@drhalathabet4977]

Where audio???

[@drhalathabet4977]

I can not follow vedio carefully

[@gumball665]

thank uu

[@헤헹-f1j]

Thank u so much!!

[@seanlim5144]

you save my day

[@gugagi29]

Really helpful.Thanks!!

[@chemist_isi]

It is pleasure for me

[@chemist_isi]

@อมรรัตน์ รัตนบุรี Could you please check below video:
th-cam.com/video/vQVCM9fb_q8/w-d-xo.html
Quality control of the analytical method control

[@Malgorbia]

Enter the I owe you my life meme