My research is activated water with plasma.. thus, some reactive species dissolved in water.. some of these species are H2O2, O3, and nitrate nitriet ion... In this case..i want to analyse the concentration of those species regard to activated time (10,20,30 minutes)...some papers said that they can be measured using UV Spec... That lead me to your video...
HELLO please can explain why the concentration of standart solution is 250 microgram? The first concentration is 100mg/l. the dilution is 25 ml with 100 ml water(100/25=4) the 100mg/l divided /4 is 25 mg/l , why is 250 microgram? I would appreciate helping in this calculation
Hi I have not been at school for probably 2 years now. I am sure the procedure has changed a lot since I left school. . Many of my videos I made early on and some I made because Covid kept students away from school. My specialty is not environmental science but a medical background. I added a few things to the procedure that may be more medical-like but information like that is in the Standard Methods book. The instructor may have made changes to fit the class since then. Another source besides Standard Methods was from manual from AWWA which may have been the big part of the procedure. The AWWA book was hard to follow and had some mistakes and at times procedures often written for people in the field, and not students. My attempt was to make a procedure that was easier to understand using a straight forward method, and to think of all the important things in a procedure including Quality Control, Proper procedure to make reagents, looking for problems and interferences in a method, and so on. I wanted to develop scientific brains, I did see that the environmental students for their DNR testing needed to know more details and numbers where it is different in the medical field where we needed to learn processes and not memorize details because details constantly change with each place you work and different instrumentations and changes with patient population
May I ask clarification about the color reagent? - How much NED, sulfanilamide and phosphoric acid did you use in the reagent? - I've also read that in most Griess reactions, sulfanilamide is added first, let to rest for 5 minutes, before NED is added. How come the reagent is only added once in this video? Thanks.
I'm sorry I have been away from school a couple of years now and my expertise is medical lab not environmental. Some of the text books have been very difficult to interpret. I hope someone here can answer your question.
No worries. What text book did you base this procedure on? According to Wikipedia, a typical commercial Griess reagent contains 0.2% N-(1-naphthyl)ethylenediamine dihydrochloride, and 2% sulfanilamide in 5% phosphoric acid, but this does not specify how much reagent I need to add in proportion to the nitrite. In this procedure, 2 mL color reagent is added to 50 mL of standard, so I'm wondering if you're using the same concentrations of NED, sulfanilamide and phosphoric acid as the "typical commercial reagent".
@@giovaniaevangelinehalim411 I used two different books for the procedures. The class had a textbook from AWWA that I took the main part of the procedure and added to it from Standard Methods. I used to call Standard Methods the bible since it was THE book for water testing
Add 100 ml of 85% phosphoric acid in 1000ml volumetric flask with 500 ml distilled water then add 10 gm of sulphanilamide dissolve it completely, then add 1 gm NED( N- 1-Napthyl- ethylenediamine dihydrochloride.mix to dissolve then finally make up up to 1000ml mark of volumetric flask with distilled water.
I'll see if I can do that. Just so you know I am a medical lab person so I do not do these tests at my main job. The students needed something easier to read. Many of the procedures we saw were confusing and missing information, mistakes, and written in difficult to understand language the people. I took the class manuals and organized it into a lab for the students. The instructor needs to still correct the lab, so It is not proof-read. The sources were Standard Methods, a book by the American Water Works Assc (AWWA), the probe owners manual, and possibly the Enviro Chemistry wastewater by Water Environment Federation
I put most of the procedure in the description of the video now. Just remember it is really a rough draft, It is the version from February 2020. I think the instructor corrected it since then. I made the video when the students were not around from Covid. If you would like me to send you a PDF I will but it does need some work
Lets say you get an absorbance of an unknown sample and it exceeds your standard curve. I know you have to dilute the sample, but how do you dilute absorbance? Or are you diluting the concentration that that absorbance gave you? Sorry
It has been a while now since I worked at the school. I do not know what a gravimetric factor is. For some of the spectrophotometer methods a longer light path gives a better absorbance difference between the standards. I remember once finding two conflicting procedures, with one saying to use the 1cm cuvettes and another using the 5cm cuvettes for a particular analyte. I believe I liked the results better with the 5. The one bad thing I found while working for the school that it was hard to find good rectangular cuvettes. We had some that did not give good results, and the good ones were hard to find.
@@MyGBLife Can you help me please, because I need to do a determination the concentration of Potassium bromate by oxidation of crystal violet at Hydrochloric acid media in bread samples .. Please I need to know how I can measureing it by using spectrophotometer ..
Can you help me please, because I need to do a determination the concentration of Potassium bromate by oxidation of crystal violet at Hydrochloric acid media in bread samples .. Please I need to know how I can measureing it by using spectrophotometer ..
I do not know if a test for nitrate in blood. I normally work in a medical lab and the only thing routinely tested similar to nitrate is ammonia. Or Blood Urea Nitrogen which a very common test. Nitrates in urine can indicate urinary infection with an organism that makes it. That is all I can think of
@@natnaelshiferaw4675 I do have a procedure on youtube testing nitrate in water using a pH probe. There may be other procedures in Standard Methods but I do not work at school anymore and I do not have access to it anymore
thank you for accompanying the video with the procedures in the describtion.. it really helps me
please help us, our nitrite linear curve not make.
if u done this process of nitrite in water, plz kindly tell me the process
My research is activated water with plasma.. thus, some reactive species dissolved in water.. some of these species are H2O2, O3, and nitrate nitriet ion... In this case..i want to analyse the concentration of those species regard to activated time (10,20,30 minutes)...some papers said that they can be measured using UV Spec... That lead me to your video...
Explained very well. It's helped me a lot. thank you so much to provid such wonderful information about nitrite in water. Love from #Bharat
How to make colour reagent for nitrite test of water ?
HELLO please can explain why the concentration of standart solution is 250 microgram? The first concentration is 100mg/l. the dilution is 25 ml with 100 ml water(100/25=4) the 100mg/l divided /4 is 25 mg/l , why is 250 microgram? I would appreciate helping in this calculation
Hi I hope someone here can help. I have not worked at the college for several years now.
Very nice video and explanation. Could you send me the protocol to prepare the color solution or post it? Thanks again.
Hi I have not been at school for probably 2 years now. I am sure the procedure has changed a lot since I left school. . Many of my videos I made early on and some I made because Covid kept students away from school. My specialty is not environmental science but a medical background. I added a few things to the procedure that may be more medical-like but information like that is in the Standard Methods book. The instructor may have made changes to fit the class since then. Another source besides Standard Methods was from manual from AWWA which may have been the big part of the procedure. The AWWA book was hard to follow and had some mistakes and at times procedures often written for people in the field, and not students. My attempt was to make a procedure that was easier to understand using a straight forward method, and to think of all the important things in a procedure including Quality Control, Proper procedure to make reagents, looking for problems and interferences in a method, and so on. I wanted to develop scientific brains, I did see that the environmental students for their DNR testing needed to know more details and numbers where it is different in the medical field where we needed to learn processes and not memorize details because details constantly change with each place you work and different instrumentations and changes with patient population
@@MyGBLife Thanks for your answer. I will try to check it on internet.
May I ask clarification about the color reagent?
- How much NED, sulfanilamide and phosphoric acid did you use in the reagent?
- I've also read that in most Griess reactions, sulfanilamide is added first, let to rest for 5 minutes, before NED is added. How come the reagent is only added once in this video?
Thanks.
I'm sorry I have been away from school a couple of years now and my expertise is medical lab not environmental. Some of the text books have been very difficult to interpret. I hope someone here can answer your question.
No worries. What text book did you base this procedure on?
According to Wikipedia, a typical commercial Griess reagent contains 0.2% N-(1-naphthyl)ethylenediamine dihydrochloride, and 2% sulfanilamide in 5% phosphoric acid, but this does not specify how much reagent I need to add in proportion to the nitrite.
In this procedure, 2 mL color reagent is added to 50 mL of standard, so I'm wondering if you're using the same concentrations of NED, sulfanilamide and phosphoric acid as the "typical commercial reagent".
@@giovaniaevangelinehalim411 I used two different books for the procedures. The class had a textbook from AWWA that I took the main part of the procedure and added to it from Standard Methods. I used to call Standard Methods the bible since it was THE book for water testing
Add 100 ml of 85% phosphoric acid in 1000ml volumetric flask with 500 ml distilled water then add 10 gm of sulphanilamide dissolve it completely, then add 1 gm NED( N- 1-Napthyl- ethylenediamine dihydrochloride.mix to dissolve then finally make up up to 1000ml mark of volumetric flask with distilled water.
Could you upload a clear copy of your instructions (and their origin) please?
I'll see if I can do that. Just so you know I am a medical lab person so I do not do these tests at my main job. The students needed something easier to read. Many of the procedures we saw were confusing and missing information, mistakes, and written in difficult to understand language the people. I took the class manuals and organized it into a lab for the students. The instructor needs to still correct the lab, so It is not proof-read. The sources were Standard Methods, a book by the American Water Works Assc (AWWA), the probe owners manual, and possibly the Enviro Chemistry wastewater by Water Environment Federation
I put most of the procedure in the description of the video now. Just remember it is really a rough draft, It is the version from February 2020. I think the instructor corrected it since then. I made the video when the students were not around from Covid. If you would like me to send you a PDF I will but it does need some work
Lets say you get an absorbance of an unknown sample and it exceeds your standard curve. I know you have to dilute the sample, but how do you dilute absorbance? Or are you diluting the concentration that that absorbance gave you? Sorry
Dilution will give the absorbance and concentration is directly proportional to that.
Thanks for your video. I have a question. Why did you use a 5cm rectangular cuvette? what is the gravimetric factor?
It has been a while now since I worked at the school. I do not know what a gravimetric factor is. For some of the spectrophotometer methods a longer light path gives a better absorbance difference between the standards. I remember once finding two conflicting procedures, with one saying to use the 1cm cuvettes and another using the 5cm cuvettes for a particular analyte. I believe I liked the results better with the 5. The one bad thing I found while working for the school that it was hard to find good rectangular cuvettes. We had some that did not give good results, and the good ones were hard to find.
@@MyGBLife Can you help me please, because I need to do a determination the concentration of Potassium bromate by oxidation of crystal violet at Hydrochloric acid media in bread samples ..
Please I need to know how I can measureing it by using spectrophotometer ..
The volume of the glass balloon bottles should not exceed.. We do not exceed the bottle volume line, it is not correct first of all...
Can you help me please, because I need to do a determination the concentration of Potassium bromate by oxidation of crystal violet at Hydrochloric acid media in bread samples ..
Please I need to know how I can measureing it by using spectrophotometer ..
I hope someone here can help with this question. I do not work at school anymore. Sounds like a major chemistry problem. Chemists please help!
Thank you for give me your time 🥺❤
Nitrat test in blood pls
I do not know if a test for nitrate in blood. I normally work in a medical lab and the only thing routinely tested similar to nitrate is ammonia. Or Blood Urea Nitrogen which a very common test. Nitrates in urine can indicate urinary infection with an organism that makes it. That is all I can think of
@@MyGBLife Can you please make a video for Nitrate in water
@@natnaelshiferaw4675 I do have a procedure on youtube testing nitrate in water using a pH probe. There may be other procedures in Standard Methods but I do not work at school anymore and I do not have access to it anymore