Standard Addition Method

In this video I describe how the 'Standard Addition Method' works. This approach provides a way of determining the unknown concentration of an analyte in a sample and is used when interferences in the sample matrix preclude the use of external standards.

[@grace5447]

I wish I had searched for this earlier. I've been crying my eyes out for hours trying to understand this thing. Now I finally understand, thank you very much.

[@waseeintemas413]

9 year later this has helped me so much understanding this Standard addition concept for my 3rd Course! Thank you!

[@eatscrickets]

Thank you for posting this video. I've used it to show my instrumental analysis students how to perform standard addition for AAS. It was easy to follow and they really liked it. Cheers!

[@AW3SOM31510]

Currently writing multiple lab reports and having a rough time up until your teaching clarity and the "Very Nice" picture at the end, thank you

[@WrongWayNinja]

I love how you explain the concept behind them and then not explain how to run the equations that's my favorite part!

[@daniyalhashmi6433]

If you still need help with equations like these when you're in instrumental analysis, you chose the wrong major lol

[@gen3ralgustav]

Very informative! I have quickly found that these types of problems are extremely subjective, so knowing the mechanics/algebra involved is crucial to solving. Thanks Dr, you are helping me save my chem anal grade! :)

[@user-kx2zs3ec3d]

My analytical chemistry teacher spend whole lesson teaching Standards addition method and I get nothing at all. But I spend few minutes watching this video before midterm and I got it all🥹 Thank for your video. You are my life saver🤩

[@dustinsmith8341]

Thank you so much. My teacher just glossed over this section and didn't explain it well because his slides were missing. I appreciate the explanation. I get it now!

[@dkreller01]

@sterling729 You are welcome. I looked for a video on this subject and couldn't find one that explained it. So, I tried to create one.

[@zeroxdude1]

Very nice video, but in my opinion the the unit for the x-axis should be in concentration to make it easier to understand how the concentration unit was obtained at the end. The volume as x-axis approach can still lead to the right answer, however it requires one to remember the concentration unit used all the way at the beginning. In addition to it being clearer, I think it would be a great way to teach the students about the importance of checking unit.

[@empirestate8791]

Summary: You basically add increasing amounts of a standard to an unknown solution and dilute them in volumetric flasks, take the concentration of each solution (using an absorbance meter or something), and plot the data. You'll get a line. The y-intercept of the line is the response when there is only an unknown solution, and the slope of the line can be used to calculate the relationship between concentration and response.
Formula: concentration_unknown = (y-intercept * concentration_standard ) / (volume_volumetricflask * slope_of_line)

[@zguitarmaster]

Empire State this makes sense... can anyone else confirm this summary? I am writing this on a flash card

[@finanhindam6332]

truly helpful !

[@igsr1869]

Thank you. Very helpful

[@imejandiskate]

I still do not understand the concept behind how adding a known amount of analyte in intervals will give you the unknown concentration. I understand the math and how to calculate the answer, I just cant wrap my head around the big picture. fuck.

[@Phaze252]

Wee bit late, but a simple way to wrap your head around it is imagining a bank account.
You don't know how much money is in this bank account and you can't just check. When you try and use the account, you're only told if you have the available money.
Now, considering how simple it is to just try and purchase many different items, this would be rather silly to do in practice but to make it work, let's say you can only attempt to purchase a brand new T.V.
Your first attempt shows you can't, so you add money to the account incrementally until you're told you have enough. Then you simply work backwards to determine how much money was in the account.
This is a little simplified obviously, but the overall principle is there.
moles of unknown + moles of standard = total response.
Once you figure out the total response how do you figure out the moles of unknown?
moles of unknown = total response - moles of standard

[@aonoymousandy7467]

Thanks for the question, this is also something that i didn't understand. Sure anyone could describe how to do a standard addition as a procedure but understanding the core concept will allow you to understand why the procedure is performed and why it works.

[@idiot33912]

thank you so much. this method makes me crazy !

[@karrarazizhassanabdullah628]

Very informative!.
Many thanks

[@Jules-tv6mx]

wow what a video thank you for all

[@prasenjitghosh2019]

Very nice explanation!

[@princessbalboa]

Thanks a lot. I wish you were my lab instructor.

[@jackjoseph3419]

I wish my quant. teacher made it this easy!!

[@SaraAlshawabkeh]

thank u so much very good explain

[@d.d.d.rukshan8835]

That was very clear! thank you!

[@fleckerz]

This is fantastic. Thank you.

[@yefected]

Thank you so much it was very helpful! What happens when the slope is negative and the relation is inverse (adding volume decreases signal)?

[@bensonhk616]

thanks a lot, you save my exam

[@yousefjokmara788]

You are my hero thanks man

[@icha1992]

for the first method, in order to find the concentration of the analyte, = (b.Cs)/(Vx.m)
-b we can get simply by taking the y-intercept.
-m we can get by finding the slope of the line
-Vx is how much volume we take from the analyte at first.
-Cs is the concentration of stock we prepare at first too right?
are these correct? or am i getting this all wrong?
Thank you so much.

[@chisomos]

+icha1992 correct

[@maharnasar9279]

Can u do one worked example.

[@thecurious2825]

thanks a lot sir....very useful,keep it up

[@suhrabsayfi1082]

Why is b/m taken? What does it give a ratio of? Unknown vs Standard?

[@adamwiesner1]

What happens if in a problem I'm given two different signals? A signal from my unknown and then a signal after the standard was added

[@maharnasar9279]

Can you do one worked example.. it looks you this video for those who knew all about it. So please do some worked examples.

[@ivanbombana7282]

In which tecnicques should I use this method?

[@rinnemollema5826]

So I feel like you're confusing Cs and Cx troughout this video in the formulas, or is that just me? 5:00 and 8:21

[@sumannallathambi8482]

Very Nice..

[@RoRight]

Great stuff

[@Agentmo485]

What is the value of Cx? The problem I have has this set of Data (Known): Cs, Vs & Vx. Where do I find the value of Cx? I cannot compute number of moles for the analyte. Please help.

[@ivanbombana7282]

Unknown & standard at minute 1:10 are the same substance?

[@irumhassan.5417]

sir is the external method of caliberation and this topic is same or not please answer me please

[@chaofang6730]

What solution was used to dilute to the flask mark line?

[@MrNabows]

water

[@VincenzoCrawford]

makes perfect sense

[@lafilosocueva721]

I have a question. How is it that you fill all flasks up to the same mark if the standard volume in each flask is variable and the unknown substance volume is constant? Am I missing something?

[@annikabaker1802]

You add diluent (usually water) in varying amounts to fill each flask up to the mark.
(I know this is probably two years too later for you, but hopefully someone else finds it helpful.)

[@GovindaGhimireus]

wow great..

[@thecasualfront7432]

make a calibration curve and divide the slope by the intercept. just don't spike your first standard with stock. forget these equations, they're irrelevant

[@hsulbjay]

GOOD !!!

[@sccm100]

I fucking hate analytical chemistry. I can't wait for it to be over