Prepare nutrient solution

[Sandae]

Hello community,

 

Now, after a very long time, I have to enter a chemistry lab again. The point is to create a nutrient solution:

5mM KNO3 (potassium nitrate),

2 mM MgSO4 (magnesium sulfate),

2 mM Ca(NO3)2 (calcium nitrate),

70 μM HBO3 (boric acid),

14 μM MnCl2 (manganese(II) chloride),

1 μM ZnSO4 (zinc sulfate),

0.5 μM CuSO4 (copper sulfate),

10 μM NaCl (sodium chloride),

0.2 μM Na2MoO4 (sodium molybdate),

40 µM FeEDTA,

4.7 mM MES,

43mM sucrose

 

How to prepare the solutions individually, eg 1 liter with 5 mn KNO3 is not a problem. But I'm a little unsure how to "combine" everything.

Method 1: Calculate for all substances how much I need for the desired concentration in 1 liter, pack them all up in a container and fill up to one liter. There would probably be too little water here due to a certain displacement effect, but with such quantities, this is perhaps negligible.

Problem: The quantities are so small that we don't have the opportunity to weigh them, even with higher concentrations and more liquid.

Consideration 2: Put all substances in the desired concentration in 1 liter (eg with the help of dilution series) and then mix everything together 1:1, for example, 100ml of everything.

Problem: Here everything would be diluted again, right? Would I then have to create everything in 12x (12 substances) before mixing it?

I would be very happy if someone could help me, unfortunately, the last chemistry class was 8 years ago.

Thank you and best regards

 

[Phi for All]

!

Moderator Note

Moved to Homework Help.

 

[studiot]

5 hours ago, Sandae said:

Now, after a very long time, I have to enter a chemistry lab again. The point is to create a nutrient solution:

Whilst your recipe list is (a bit) interesting you haven't said how much solution you require or what the form of your ingredients are.

Considering you are not requiring analytical chemistry accuracy I think you could just scrape into the pharmaceutical balance category.

Most of your ingredients require millimoles per litre which would cause no difficulty.

The heavy metal sulphates have a MW of around 160 so you would be requiring about 0.1 - 0.2 millig/litre

So if you could accept making up a large solution of these and pipetting or buretting some you could maybe get away with that.

https://www.pharmaguideline.com/2014/09/calculation-for-weighing-range-of-balances.html

 

If you don't know how to use a balance, you need technician assistance.

Here is a standards pdf on preparing mixed solutions.

https://www.training.nih.gov/assets/Lab_Math_II_Transcript_-_508.pdf

 

 

 

 

[CharonY]

It looks very much like a micronutrient solution to me. If that is the case, I would ask the the lab for their SOP, as differences in preparation, especially with metals, can result in differences in the experimental outcome.

But the general procedure is to weigh in the required amount into volumetric flasks and fill up to the indicated volume. If the weight is too low, one can increase the volume or create stock solutions (either of the whole mix or of each compound individually), which depends a lot on the solubility of the components and possible cross-reactions.

[Sandae]

21 hours ago, studiot said:

Whilst your recipe list is (a bit) interesting you haven't said how much solution you require or what the form of your ingredients are.

Considering you are not requiring analytical chemistry accuracy I think you could just scrape into the pharmaceutical balance category.

Most of your ingredients require millimoles per litre which would cause no difficulty.

The heavy metal sulphates have a MW of around 160 so you would be requiring about 0.1 - 0.2 millig/litre

So if you could accept making up a large solution of these and pipetting or buretting some you could maybe get away with that.

Hello, Thank your for your help!

By now I will probably do it with Stock solutions with a higher M concentration and then pipetting it according to the wished cocnentration in the working solution. Pipetting with those small values is possible for us.

Thank you again!