Determination of Peroxide Value_A Complete Procedure (AOAC 965.33)

[@mariovendrell3563]

I am doing a PhD in oil quality and I found this video very interesting. Thank you very much, you are great!

[@MicroChemsExperiments]

Glad it was helpful!

[@نور-ذ5ع9و]

Hello.. Have your Facebook account available?

[@shraddhapiligaonkar3639]

I want a procedure for preparation of 0.5 N alcoholic KOH

[@chemsciences126]

kzbin.info/www/bejne/n3Kvip-uetKBe7s

[@chemsciences126]

Dear Mario Vendrell Your are doing good. It's my channel, hopefully, my videos will also helpfull to you. Thank u

[@suhanamughal1103]

This video was very clear and help full. Thank you for the effort👍🏻

[@MicroChemsExperiments]

You are welcome

[@prathameshmhatre1211]

Thanks I have my practical exam and this helped a ton!

[@MicroChemsExperiments]

Great to hear!

[@AleksandraVikol-uj4vi]

Thnx a lot for your efforts it’s wonderful to have such explicative tutorials. I would like to ask just one question about standardizing a 0,01N tiosulfate with K dichromate, its a crucial and obligatory step in preparation of titrant solution? Thank you in advance!

[@maryamnisar9697]

Very nice description!!! I have watched the whole video Also good presentation Keep it up!!!!!

[@MicroChemsExperiments]

Maryam Nisar, thank you very much. Many upcoming videos are waiting for you. Be with us.

[@AbhishekSharma-mo3nb]

Keep it up Doing great 👍 And thanks for vedios

[@MicroChemsExperiments]

Thanks

[@yogeshmandole5953]

Please keep going, this is really helpful

[@abianand9582]

Super . Your effort is nice and best hard working . Thank you

[@MicroChemsExperiments]

Thank you

[@imandyadharmathilaka739]

Thanks for this great video! Can you explain how standardized the preparade 0.01N sodium thiosulpate solution with potassium dicromate. How much we need to add?

[@MicroChemsExperiments]

Follow this video: kzbin.info/www/bejne/jmOuo3Wco7CqaJY

[@miguelangelruiz1114]

Great video and helpme a lot, and so ¿This techique work for oils of animal origin? thanks!!

[@MicroChemsExperiments]

Yes

[@yuniastria5432]

I suggest to do peroxide value analysis in safety cabinet

[@lorenzycodo697]

Hi, how do we calculate the normality of sodium thiosulphate? Thank you for this very informational video.

[@MicroChemsExperiments]

kzbin.info/www/bejne/jmOuo3Wco7CqaJY

[@keshavtat8471]

Yes but confusing me between 0.1 N thiosulphate and 0.01 N thiosulphate Plz tell me how to make 0.01N and standardize.

[@thidieuvypham5326]

Hi. Thanks for the great video! Could you inform me why we have to use acetic acid-chloroform solution but not other solutions ?

[@MicroChemsExperiments]

AOAC method said so. We will make video later explaining the mechanism of chemical reactions.

[@sujisujith476]

Hello.. Is there any relation between free fatty acid and peroxide value?? Means if i get Free Fatty Acid high then should i get peroxide value also high?? Plz relpy

[@ruchirdave2823]

Hello, Thanks for the video it was very informative I want to know whether this method is useful for excipient study?

[@MicroChemsExperiments]

Yes. Useful

[@nonavancoillie900]

For acetic acid, can you also use the acetic acid you use in the kitchen?

[@MicroChemsExperiments]

No. The acetic acid in your kitchen is in food grade quality. In analytical laboratory, always use analytical grade of chemicals.

[@happyneal1618]

May I know thr effecta of Acetic Acid, Potassium Iodide, Water, and Starch soluble in the solution? Also, is the measurement of the reagents added in the solution should be accurate and in order? Thank you.

[@RupinderKaur-n6c]

Good video guys keep growing

[@MicroChemsExperiments]

Thanks. Stay with us

[@engfatmaabomosa803]

Thanks for your efforts, please can you explain that high value? You know that the value of oil peroxide must be on range from 0.6 to 0.7 in final product , l did the experiment but the value was very high!!!

[@MicroChemsExperiments]

High peroxide valo means low quality oil or very rancid oil. The oil that has been degraded its component.

[@engfatmaabomosa803]

@@MicroChemsExperiments thank you so much 😍🥰

[@nayabghori5934]

can we also calculate tocopherols by this titration method ?

[@SamiraHammouti-h7q]

Excuse me, doses the standarisation very important ?

[@hafezquadri2972]

For oils we can use sample directly for analysis.. But could u please tell me how to test a food sample ..any digestion process is required??

[@MicroChemsExperiments]

To test a food sample, you have to extract fat or oil content from your food sample first, following our video: kzbin.info/www/bejne/aGXUiImCopybntk After extraction of Fat or oil, use the extracted fat/oil to test for peroxide value by following this video.

[@hafezquadri2972]

@@MicroChemsExperiments ok thank u..I know about the soxhlet extraction process. Since it is a lenghty process iam looking for any alternative method ...plz do let me know if an other .tq

[@MicroChemsExperiments]

@@hafezquadri2972 No other method known to me except extraction of fat

[@Zeeshanxjs]

You didnt proformed this procedure accroding to AOAC method. you must titrate the oil after adding the potassium iodide to remove yellow color and then add the starch solution then again titrate to remove bluish color

[@vishmithabsshettigar6700]

Was very clear and a nice explanation...Thank you😊 Can you please clarify my doubt regarding how to standardize the prepared solution of sodium thiosulphate with potassium dichromate...Plz🙏

[@MicroChemsExperiments]

Already uploaded in another video. Please find it in this channel

[@zz-kc9mc]

Is it inappropriate to stop titration when the solution's top part turns into white?? not the whole part. In our lab, we stop titration when the top part turns into white.. I want to know is there any difference between these two methods.

[@newsofislam1284]

After adding Saturated KI solution may need to insert corck immediately?

[@MicroChemsExperiments]

Yes

[@newsofislam1284]

You are not showing that.

[@MicroChemsExperiments]

@@newsofislam1284 That was our error occurred to make the video faster. But you should follow what you said in your lab

[@newsofislam1284]

Thanks a lot.

[@rajesh7999]

You can add the use of test for beginners so they can know immediately...thank you...good experiment channel keep going

[@MicroChemsExperiments]

NUTHAKKI RAJESH, thank you for your comment. Surely we will add uses of the test in the video description. Keep supporting us.

[@ajforeversmiley2641]

When I add the 1% starch solution, there is no colour change. What am I doing wrong?

[@MicroChemsExperiments]

Ajforeversmiley, Possible two reasons for no color change after adding 1% starch are given below: 1. May be the starch solution is not freshly prepared. 2. May be your sample have very low peroxide value.

[@islascel2652]

@@MicroChemsExperiments If the color does not change even though I prepared it fresh, is the starch powder I use spoiled?

[@MicroChemsExperiments]

@@islascel2652 No, we can not say directly that starch powder is spoiled if color does not changed. when we add starch solution, amylose forms a blue to black solution with iodine. So if your sample does not contain iodine then black color will not be formed. The peroxide value is determined by measuring the amount of iodine which is formed by the reaction of peroxides (formed in fat or oil) with iodide ion. So, if color does not changed, interpret the Peroxide value result as 'Nil'

[@motivationpk123]

You could try heating the starch solution before adding it. Worked for me

[@29moch.syarifbisma.a6]

@@MicroChemsExperiments Btw When i added Starch first before Distilled water, the black/blue colour is appear Is that true?

[@arslanmunir9334]

Which type of starch is use as an indicator? It available as rice, potato and other starch. Can you please specifies its type?

[@MicroChemsExperiments]

Use reagent grade starch which is soluble in warm water

[@motivationpk123]

Do you need a blank titration too for the analysis? Some people do a separate titration for the blank sample. Then subtract the titre value of the blank from the sample(Vs-Vb). Before putting that value into the calculation

[@MicroChemsExperiments]

Yes. you can conduct blank titration to get the more accurate result. But without blank titration you can also get a acceptable result.

[@motivationpk123]

Should the blank give a higher or lower titre value?

[@evancbiju474]

Thank u👏Where did that 1000 in the calculation come from?

[@MicroChemsExperiments]

Calculation factor

[@evancbiju474]

@@MicroChemsExperiments How can we find that?

[@RJ10911]

Thanks a lot for making video on this reaction. For few mineral oil we check we didnt get yellow colour after add of ki.so we consider it as a nil. U hv used conc acetic acid. We use diluted as per our sop borrowed fm renowned customer. Will it make diff huge diff.

[@MicroChemsExperiments]

You should use concentrated acetic acid as said in AOAC.

[@ehsanasghar7448]

thanks, it is very helpful.

[@ishaursekar9916]

I am using olive oil, and since chloroform is not available in my school, can I use dichloromethane as a solvent instead of the chloroform-acetic acid mixture?

[@MicroChemsExperiments]

Never find any reference of using dichloromethane. So, no idea

[@lingalaschool4428]

Thank you for ypour video, i need to check peroxide value in macadamia nuts. Do i have to extract the oil from them or i can grind them into poweder and then add distilled water or (what chemical can be added to extract) and shake. which is the easier way. If i have to extract oil which is the method? Thank you

[@MicroChemsExperiments]

If you extract the oil from your sample and do the analysis then it would generate more accurate test results. You can extract the oil by the method of fat extraction using n-Hexane or petroleum ether

[@Akbar-jw3oi]

Can you please do how to check p anisidine value in oil

[@dianareyes7371]

What if the sample is expected to contain iodine? Would this protocol still be applicable since it is using KI as a reagent? Thank you.

[@MicroChemsExperiments]

Yes. Same protocol should be followed

[@rohitrajput8241]

Dear sir/mam please make the video of dailation test of vanaspati ghee

[@MicroChemsExperiments]

Will try

[@luzdelunalopezaleman9260]

Hola, buenas tardes. Podría aclararme una duda que tengo?

[@MicroChemsExperiments]

Yes. Sure. Write us at [e-mail]

[@QuanMinh-et1dm]

Can I measure the Peroxide Value while the oil is still hot? Thank you for the great video by the way!

[@MicroChemsExperiments]

Yes. You can.

[@trucminguyen9510]

Please help me explain, In this test, do we need to titrate the blanc sample? This video are very helpfull, thank you so much.

[@MicroChemsExperiments]

Yes. We need to tritrate our sample after dissolving in ethanol by heating.

[@trucminguyen9510]

@@MicroChemsExperiments how to titrate the blanc sample? Can i change sample test to distill water

[@kimmytran9973]

@@trucminguyen9510 in my lab we titrate the blank the same as the sample, except that there’s no oil added. Blank reading less than 0.05ml is acceptable in my lab.

[@trucminguyen9510]

@@kimmytran9973 thank you so much

[@EliElordi]

@@kimmytran9973 hi, may I know how your side prepare the blank? I did follow the method but my blank always end up higher than 0.10, often I get around 0.30 to 0.70ml which is quite high. The procedure I use is as follow: 1) 50ml acetic acid/isooctane into 250ml flask 2) add 30ml reagent water, swirl to mix and add 1ml saturated KI 3) Add 0.50ml starch (blue colour appears) and titrate to endpoint (white). What would cause my blank to be so high? I did prepare new starch and new KI solution but still can't get low blank

[@IrfanAli-xy5bf]

Miss kindly share rencidity and FFA testing procedure of shortening. Thanks.

[@MicroChemsExperiments]

Irfan Ali, you can find FFA from acid value of an oil sample and Acid Value determination procedure is already uploaded. We will upload Rencidity determination procedure very soon. Thank you for being with us.

[@rowidakhalily5760]

Plz tall me what is 26.5 . Because you did just one time titration

[@kathirvelk7006]

Good explain sir thank you sir

[@MicroChemsExperiments]

Thank you. Stay with us

[@jo-pr2zd]

Why did you add sodium carbonate?

[@MicroChemsExperiments]

Standardization method said so

[@udaykumarkachrola7494]

Why you add .02g Sodium carbonate in Sodium thiosulfate solution ?

[@MicroChemsExperiments]

AOAC method said so

[@doobydoes4956]

I read you can use cyclohexane for the organic solvent instead of chloroform. Is that true?

[@doobydoes4956]

CYCLOHEXANE DOES INFACT WORK. YOU NEED TO PIT IN 3 GRAMS OF SAMPLE, 50ML ORGANIC SOLVENT AND 100ML WATER 🔥

[@MicroChemsExperiments]

Yup

[@shailesh6948]

Blue colour not appear after adding starch solution

[@shraddhapiligaonkar3639]

Is there any replacement for chloroform can dichloromethane be used in place of chloroform?

[@MicroChemsExperiments]

Not sure and no replacement to be known actually.

[@Farmville91]

Can you use acetic acid / Isooctane, instead of the chloroform? And this and all your videos are very HELPFUL!! Thank you!

[@MicroChemsExperiments]

Thank you so much for your comment. No, you can't use any other chemical replacing the chloroform in this test.

[@iamjhentayoto9662]

Yes.. For safety reason, they allow to use isooctane in replace of chloroform

[@banderali-v4g]

thanks for the great video

[@SharifulIslam-kb7jd]

Your caption says you are determining Peroxide value but during the calculation you said acid value 4.09 meq/kg

[@MicroChemsExperiments]

It was a slip of tongue. You did mistake in sayings. It should be peroxide value. We actually determined peroxide value in this video. We are very sorry for our mistake.

[@wasifurrahman9156]

we are getting a high titration value for blank comparing to sample. what should be possible issue in our method?

[@oang1760]

i have the same issue, need a lot of titrant for blank

[@khandhanish6154]

Sir may be most of the oil are not showing blue colour when added the starch solution...

[@MicroChemsExperiments]

Color depends on the peroxide value of sample. Without blank conduction, you can get the accurate results by following this video.

[@khandhanish6154]

Total 2percent contain.......so it will show blue or not?

[@hinachi-9841]

The problem is i don't have any of this equipments, even the liquids. Im a student and we need to test the peroxide value of our oil. Help me pls

[@MicroChemsExperiments]

Contact a laboratory around you

[@mariaph9700]

Does it matter if I add the thiosulfate while stirring or not? When I add thiosulfate and wait a little bit versus when I add it while stirring, it yields 2 different results. I am not sure which is right. Please help me explain. thanks

[@MicroChemsExperiments]

Add thiosulfate while stirring

[@mariaph9700]

How fast should I add it?

[@khengsovanchhay5196]

May I know what is we don’t add 30ml of dw what will happen

[@impostorMotoTV]

Thank you for sharing this information.

[@MicroChemsExperiments]

Norman Guanizo, you are welcome

[@impostorMotoTV]

MicroChem's Experiments do you have details on how create citric acid sulotion for physical degumming. Let say i have 1L of coconut oil how much citric acid and water to mix to perform degumming.

[@umaimakamal9795]

My teacher asked what is the relationship between cloud point and melting point do u know?

[@MicroChemsExperiments]

Take help from Google

[@halaawwad2143]

Should you do the plank experience? If so, how?

[@MicroChemsExperiments]

The question is not relevant to the video

[@sarahkhan9988]

Wow this video is really helpful for me thanks❤!! Can I know why the unit is in per kg, when we use our oil sample in gram for the calculation though?

[@MicroChemsExperiments]

Look at the calculation again. It was multiplied by 1000 to covert the value into Kg.

[@Yu-Lin-s4n]

Sorry, why must add 30 mL distilled water and shake 1 min to mix ? I would thank you very much😢

[@MicroChemsExperiments]

In large volume of solution, the color of the end point of the titration is more easier to be seen. Water is added to increase the volume of the solution

[@morszepesi415]

Thanks for the great video! Could you please give the different chemical reaction equations for each step? Thanks.

[@MicroChemsExperiments]

Great suggestion! Soon

[@sarahbensoula3378]

hello, please can you tell me if i can use this method if i have a really small amount of fat (extracted from a muscle), if not can you recommend me a better method to determine the peroxide value. thank you.

[@sadiyasajad8176]

Hello mam.. I wanted to know if i had to calculate the peroxide value of meat sample.. Is it that i had to extract the fat using soxhlet method and to that extracted fat only i can go for checking peroxide value... Cant i homogenise the meat samlpe directly in water and check the peroxide value of the homogenised sample..

[@MicroChemsExperiments]

You can check peroxide Value directly using the blended meat sample.

[@isurikavindiamarasingha855]

I tried this one but when I added starch solution, no blue or black colour produced. What is the reason for that?

[@MicroChemsExperiments]

Prepare your reagents freshly and try again. If same result found, you can interpret the result as 'Nil'

[@pukhrajchhipa773]

Range of peroxide value in soyabean refined oil ????

[@MicroChemsExperiments]

Take reference of ranges using Google

[@shraddhapiligaonkar3639]

How to prepare wijs reagent using ICl

[@MicroChemsExperiments]

We will make video later. Till then, purchase prepared wij's solution

[@shraddhapiligaonkar3639]

But at least tell me the procedure

[@SwhyBe]

For sodium thiosulfate I found supplier that sell this solution and its standard already ? Do I need to standardise it after opening?

[@MicroChemsExperiments]

No need to standardise again.

[@chuqiaomai290]

Can you use this method to determine peroxide value in dried milk powder?

[@MicroChemsExperiments]

Yes. You can

[@chuqiaomai290]

@@MicroChemsExperiments Great thank you so much! Do I need to extract fat from the powder first or the method can be applied to milk powder directly?

[@MicroChemsExperiments]

You have to extract fat first using Hexane or Ether solvent. Then go for the analysis

[@noorinoora2627]

Why when i put starch the sample not turning blue/ black it just white

[@MicroChemsExperiments]

Prepare chemicals freshly and try again

[@ovaneschakoyan6584]

is it necessary to shake the sample with potassium iodide in dark conditions or this is has no influence on analysis.

[@MicroChemsExperiments]

You dont need to keep the sample in dark after adding KI solution.

[@munmunkundu9033]

Can i do this experiment with maize parts

[@MicroChemsExperiments]

No idea. You can try

[@jancy98]

Can u plz share the calculation for the amount of sodium thiosulphate to taken in reagent preparation?

[@MicroChemsExperiments]

Please take help from Google

[@vineetpal4789]

You are great😂❤❤❤

[@MicroChemsExperiments]

Thank you

[@oumaimaazakak7285]

Hello Miss, please I wanna know the average of peroxide value that we can get in our experiment for known is the oil have a good quality or not and thanks in advance.

[@MicroChemsExperiments]

Lower peroxide value indicates the good quality of oil. Quality decreases with the increasing peroxide value.

[@oumaimaazakak7285]

Thank you so much 🥰

[@oumaimaazakak7285]

I have another question about the blank, when I use a blank in this experiment and start my titration on it With thiosulfate of sodium what's the value shall I get when my blank pass to a colorful solution to a colorless solution.

[@MicroChemsExperiments]

@@oumaimaazakak7285 It varies with many conditions or parameters. Plz conduct the test in your lab to get the more idea.

[@souravsarkar4497]

Thanks for making this video

[@souravsarkar4497]

Can you prepare ' oxidation value of oil' video ?

[@MicroChemsExperiments]

@@souravsarkar4497 You are welcome. Noted the parameter. We will work on it.

[@souravsarkar4497]

@@MicroChemsExperiments i couldn't get this video

[@MicroChemsExperiments]

@@souravsarkar4497 Why? Which part of this video is not understandable to you? I think it's a clearly explained video.

[@souravsarkar4497]

@@MicroChemsExperiments i want to know oxidation value of oil and fat

[@bablubadmash9408]

0.5 g starch soluble added in how much ml of water?

[@newsofislam1284]

50 ml

[@devanshdesai1811]

Thank you for this video. As per ISO and FSSAI manual, there is a step "Titrate with 0.1 N sodium thiosulphate solution with constant and vigorous shaking. Continue titration until the yellow colour almost disappears. Add 0.5 ml of starch solution and continue titration till the blue colour just disappears." AOAC has also mentioned the same. But most of the industries also don't follow this step. They generally do titration directly after adding starch indicator. You also did not followed this step in video. Can you please give some clarity on this?

[@MicroChemsExperiments]

The type of the titration is two steps titration, so it should be completed separately in two steps to get the more accurate results as suggested by AOAC.

[@nasabanicholas8496]

Very helpful

[@MicroChemsExperiments]

Thank you

[@gadajacygad8300]

In your calculations you've calculated the normality of Sodium Thiosulfate. As far as I know equation for normality is N=M*n . Where M is number of moles per Litr and n is the n-factor. In your experiment you used 0.01M Sodium thiosulfate so M=0.01. And I think that the n-factor of Sodium thiosulfate is 2 as it dissolves into 2Na+ and (S2O3)2-. So 0.01*2=0.02N. Nevertheless, in your calculation you've written that N=0.01. Is it a calculation mistake or I don't fully understand calculations? I need this information because I need to calculate the peroxide value in my experiment.

[@MicroChemsExperiments]

Gadajacy Gad, We used 0.1M sodium thiosulfate solution in this test. You can look at our preparation of sodium thiosulfate. We diluted 25g sodium thiosulfate crystal in 1000ml water which makes 0.1M sodium thiosulfate. But in sayings and in the subtitle we said about 0.1N instead of 0.1M. It was our silly mistake. Just avoid the mistake and forget about Normality. You can follow the whole calculation and method strictly to test the peroxide value. So ignore about normality and consider 0.1N as 0.1M. It should be 0.1M, not 0.1N. Thanks for your observations.

[@gadajacygad8300]

@@MicroChemsExperiments Thank you for explaining it to me

[@MicroChemsExperiments]

@@gadajacygad8300 you are most welcome.

[@dilshaniweragama7227]

@@MicroChemsExperiments But you mentioned that you diluted 0.25 sodium thiosulfate in 100mL of water (0.0025),and here you mention that you dissolved 25g in 1000ml (0.025). which method is the correct one? thanks.

[@Kindly_Her]

Where is the 1000 coming from😢, i am confused 😊

[@arslanmunir9334]

I am facing the problem related to Indicator. When I add 1% starch indicator ,No Color change observe. Can you please resolve this issue OR give any suggestion?

[@arslanmunir9334]

As I use freshly prepare KI and Starch Indicator.

[@sweathaswea4660]

Can we use for titration 0.1 n sodium thiosulfate

[@MicroChemsExperiments]

No. If you use 0.1N instead of 0.01N then you will not get the accurate result of peroxide value.

[@azaruameer3931]

Can you give me the "Determination of Oil Analysis" manual if I need it?

[@MicroChemsExperiments]

We do not provide any document

[@SwhyBe]

I have tested body oil of brand and peroxide value is 34 does that mean is not good in quality ?

[@MicroChemsExperiments]

Yes. Not good in quality of that oil

[@29moch.syarifbisma.a6]

In my Lab. While shake/mix The Erlen must be Close with Tube for erlenmeyer Is that True?:/

[@MicroChemsExperiments]

Yes. True

[@29moch.syarifbisma.a6]

@@MicroChemsExperiments can you give me the reason, why we do that? :/

[@MicroChemsExperiments]

@@29moch.syarifbisma.a6 Volatile compounds are form in the flask afrer mixing the chemicals with samples. Cap should be used to avoid the escape of the volatile matter from the flask.

[@29moch.syarifbisma.a6]

@@MicroChemsExperiments oh ok, thank you :D

[@MicroChemsExperiments]

@@29moch.syarifbisma.a6 You are welcome

[@SohelRana-ln7bg]

Pls make the video of preparation & standardization 0.1 N/M of Potassium Dichromatte

[@MicroChemsExperiments]

Ok. We will make. Please stay with us

[@khandhanish6154]

Sir When I was use starch solution no blue colour observed....

[@khandhanish6154]

What is the error

[@MicroChemsExperiments]

Prepare starch solution and potassium iodide solution freshly just before the analysis.

[@khandhanish6154]

Which starch are used basically Maize Starch or soluble starch

[@MicroChemsExperiments]

Soluble starch should be used.

[@khandhanish6154]

But I not get the result

[@factxfact5549]

Is peroxide value test enough to check if the oil is rancid or not?

[@MicroChemsExperiments]

No. Not enough. Peroxide value just gives an primary indication of Rancidity. You must go for the rancidity test to confirm. We have recently uploaded Rancidity test video. Plzz follow that video for details about rancidity test.

[@MrLongKR]

Which AOAC method is the reference for this?

[@MicroChemsExperiments]

Reference is given in the video title

[@MrLongKR]

@@MicroChemsExperiments oh yeah! Sorry I missed that! Thank you

[@MicroChemsExperiments]

@@MrLongKR no problem sir. Thank you

[@lorenzycodo697]

please please can you explain how to standardise the sodium thiosulphate

[@MicroChemsExperiments]

kzbin.info/www/bejne/jmOuo3Wco7CqaJY

[@meltunivers6475]

thank you so much for this video

[@MicroChemsExperiments]

You are most welcome.

[@rashibhasan873]

Dear, Mam. I prepared Sodium thiosulphate (0.01N) solution using your formula and tried to determine the peroxide value.But Blue color of the final mixture is not changing even after adding more than 100 ml (Na2S2O3.5H2O). Then my prepared soln even is not working during standardization of sodium thyosulphate by K2Cr2o7. Where is the problem mam,Is there any problem in Na2s203.5H2O solid.

[@MicroChemsExperiments]

Yes. May be there is a problem with your sodium thiosulfate crystal. It should not be happened what you said. Otherwise there is problem in glassware and apparatus cleaning. Plzz watch the video again and do the experiment again using clean glassware and apparatus and preparing chemicals and reagents accurately & freshly. After that let us know the result. We will try to find the problem and give you a solution.

[@rashibhasan873]

@@MicroChemsExperimentsi tried and still trying to solve the problem. I cleaned my apparatus using 32% HCL, then washed several times with Distilled water and dried using hot plate and the burette was rinsed by the sodium thyosulphate solution. Using your video I determined acid value successfully but in determining peroxide value it is not working. I used freshly prepared KI and starch indicator and as the solution turns to blue implies that both KI and starch indicator are in good condition but problem crops up when using sodium thyosulphate. So where is the problem.

[@MicroChemsExperiments]

@@rashibhasan873 Test another sample brought from local market and test again. If your problm is not solved then replace sodium thiosulfate reagent by a new one of good brand & supplier.

[@rashibhasan873]

@@MicroChemsExperiments I conducted the experiment several times but it is not working.I am currently using sodium thyosulphate pellets imported from Merck specialities Private Ltd, Worli, India. Which brand should I use instead to get over this problem?

[@MicroChemsExperiments]

@@rashibhasan873 before changing the chemicals, conduct a test for another saybean oil sample purchased from the local market.

[@Rahulpatle-14]

nice work

[@MicroChemsExperiments]

Rahul Pawara, Thank you.

[@SohelRana-ln7bg]

How to standardize sodium thiosulfate by patassium dichromate?

[@MicroChemsExperiments]

Link: kzbin.info/www/bejne/jmOuo3Wco7CqaJY Did you watch my video list. Please search your asking test from my video list.

[@Krhula]

What research question can be formed out of this experiment for IB experiment?

[@MicroChemsExperiments]

Thanks for asking tha question but we have only concern with the experiments, relating our videos. We have no idea about questionnaire and we are very sorry for that.

[@sweathaswea4660]

When I m adding starch solutions tha sample colour not turn black colour it will be in yellow (for ghee sample ) give me solutions

[@MicroChemsExperiments]

Prepare potassium Iodide and Starch solution freshly on the day of analysis.

[@SwhyBe]

Great video can please mention the concentration % of acetic acid

[@MicroChemsExperiments]

We used Glacial Acetic Acid (99.5%)

[@SwhyBe]

@@MicroChemsExperiments perfect one more question can I purchase 0.0109N solution already prepared and standardised will it work for this experiment?

[@MicroChemsExperiments]

@@SwhyBe Yes. You can purchase 0.01N solution from local market and can use in this experiment. If you face any difficulty to purchase they follow our video for the preparation and standardization: kzbin.info/www/bejne/jmOuo3Wco7CqaJY

[@SwhyBe]

@@MicroChemsExperiments its not 0.01N actually it is 0.0109 N will this effect the experiment?

[@MicroChemsExperiments]

@@SwhyBe No problm with it

[@shwetabhoir9403]

can you share determination of Methylene blue value of carbon

[@MicroChemsExperiments]

Noted.

[@lakshmanubodireddy2763]

Hi..I tried to this method in lab but when add starch solution no any dark blue changed

[@MicroChemsExperiments]

If you are doing this test for the first time then try with a known common reference sample

[@lakshmanubodireddy2763]

Tq..sir

[@lakshmanubodireddy2763]

Kindly to tell me which oils sample I have to take .... yesterday analysised more rice born oils sample when I added starch solutions no one sample changed colour