Waffles SS
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Making Determination Kit
I create this topic for collecting information about making Determination Kits
Please post your information about making these Kits
[Edited on 1-7-2016 by Waffles SS]
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Waffles SS
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Total hardness
I found below procedure after searching in google.
If someone have better procedure then post it
Reagents
Ethylenediaminetetraacetic acid (EDTA), disodium salt, dihydrate (not less than 99%purity). Dry for 2 h at about 800C
before use.
Calcium carbonate (not less than 99% purity). Dry for 4 h at about 1050C before use.
Sodium hydroxide. 2 mol/l solution. Dissolve 8 g of NaOH in 100 mL of freshly distilled water. Store in a
polyethylene bottle. Take precautions to avoid contamination by atmospheric carbon dioxide.
Buffer solution. Dissolve 67.5 g ammonium chloride (NH4Cl) in 570 mL of ammonia solution (25% m/m, ds 20 = 0.910
g/mL). Then, add 5.0 g of the disodium-magnesium salt of EDTA and dilute to 1000 mL with deionized water.Store in a polyethylene bottle.
Dilute 10 mL of the solution to 100 mL with water. If this solution fails to give a pH value of 10 + 0.1, discard the original solution.
EDTA solution, 0.01 mol/L.Dissolve 3.725g of EDTA disodium salt in deionized water.Transfer, quantitatively, to a 1000 mL
volumetric flask and make up to volume with deionized water. Store in a polyethylene bottle.
Standard calcium solution. Weigh (to the nearest 0.1 mg) 1.0 g of dried calcium carbonate and transfer to a 500 mL
conical flask. Add slowly (drop by drop in the beginning), 21 mL of 1 mol/L hydrochloric acid solution. Swirl the contents of the flask
until all the carbonate is dissolved. Add 200 mL of water, boil to expel the carbon dioxide and cool.
Add a few drops of methyl red indicator solution and adjust to an intermediate orange colour with 2 mol/L ammonium hydroxide
solution or 1 mol/L hydrochloric acid solution, as required. Transfer, quantitatively, to a 1000 mL volumetric flask and make up to
volume.
1 mL of this solution = 1 mg calcium carbonate.
Mordant black 11 (Eriochrome black T) (C.I. 14645), 0.5% solution. Dissolve 0.5 g in 100 mL of ethanol-water (80 + 20, v/v).Or
alternatively, dissolve 0.5 g in 100 mL of triethanolamine. Up to 25 mL ethanol may be added instead of triethanolamine to reduce the viscosity of
the solution. The indicator solution is used in the determination of the total hardness of water.
Solochrome dark blue (calcon) (C.I. 15 705), 0.5% solution. Dissolve 0.5 g in 100 mL of methanol.
Or alternatively, use the: HSN indicator (calcon carboxylic acid) {2-hydroxy-1-(2-hydroxy-4-sulfo-1-naphthylazo)-3-naphthoic acid}.
Mix 0.2 g HSN indicator and 100 g of sodium chloride. These indicators are used in the determination of calcium.
Procedure
Standardization of EDTA solution(4.1)
Pipette 20.0 mL of the calcium standard solution into a 250 mL conical flask and dilute to 100 mL, preferably with deionized water. Add 4 mL
of the buffer solution and 6 drops of the Mordant black 11 solution. The colour of the solution should now turn to claret or violet and its pH
value should be 10.0 + 0.1.
Titrate with the EDTA solution, rather rapidly at the beginning and slowly towards the end of the titration. Add the EDTA
solution until the colour of the solution starts to change from claret or violet to blue and then to a distinct blue endpoint (t mL). 1 mL of
the EDTA solution equivalent to calcium carbonate (in mg)
E(CaCO3)=20 x 1mg(CaCO3) / t
Determination of total hardness (calcium + magnesium) of water In case of WHO standard hard water:
Pipette 50.0 mL of the sample into a 250 mL conical flask and dilute to 100 mL,preferably with deionized water. Add 4 mL of
the buffer solution and 6 drops of the Mordant black 11 solution.
Titrate with the EDTA solution as described in 4.1 to a distinct blue endpoint (v mL).
CaCO3 content(in mg/l)= v x E(CaCO3) x 1000 / 50
Determination of calcium in presence of magnesium
Pipette 50.0 mL of the sample into a 250 mL conical flask and dilute to 100 mL,preferably with deionized water. Add 2 mL of
2 mol/l of NaOH solution and approximately 0.2 g of the HSN indicator or 6 drops of the Solochrome dark blue
solution. The colour of the solution should now turn to claret or violet and its pH value should be at least 12.0.
Titrate with the EDTA solution as described in 4.1 to a distinct blue endpoint (v1 mL).
CaCO3 content(in mg/l)= v1 x E(CaCO3) x 1000 / 50
Determination of magnesium
The magnesium present in the sample may be calculated by substracting the volume of EDTA solution required for the calcium determination from the
volume required for the total hardness determination, for equal volumes of the sample.
1 mL 0.01M EDTA = 0.2432 mg magnesium
source:http://www.who.int
[Edited on 1-7-2016 by Waffles SS]
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NEMO-Chemistry
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Not sure if it helps but, i found a site that lists the MSD's of various aquatic test kits etc. It might give you an idea of what is in various
determination kits
http://www.regulatory-info-hsx.com/
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Waffles SS
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@NEMO-Chemistry thanks,
It will help us to find out what is material of each one
I really want to know material and it concentration in aquatic test kit
[Edited on 1-7-2016 by Waffles SS]
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Argentum
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Merck sells a total hardness test. Loking at the MSDS may help. Unfortunately they are way too expensive to me, so I use the analytical method. The
only difference is that I prepare the eriochrome solution by dissolving of 0.5 g of it in 100 ml of ethanol and then I add 4.5 g of hydroxilamine HCl.
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NEMO-Chemistry
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I cant find the link at the moment, but somewhere in my bookmarks i have a site that lists thousands of products MSD's. From water test kits to all
sorts, alot of the MSD's were apparently sent off for and scanned, soon as i find it i will post.
The hagen one i posted isnt great, but the amonia test etc tells you what is in them, then look up the actual test kit instructions, this will tell
you how much water to put in and how many drops from each bottle, that way you can work out the concentrations!
I have used it for replicating a simple soil test kit for iron.
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NEMO-Chemistry
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An example from the link i gave http://www.regulatory-info-hsx.com/pdf/english/MSDS-A7821.pd...
this is the ammonium one for fresh water, now look at the test kit instructions.
Ok bad choice i couldnt find it!! but its out there. Anyway here is another instruction set from a different kit they do
http://ca-en.hagen.com/File/53d811fe-d647-4353-b3dd-2205b995...
so using the data sheet and the kit instructions you can work out how to make your own kits.
Sorry i made it sound very confusing! might have to change my name to Allan 
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NEMO-Chemistry
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http://www.msdssearch.com/ManuflinksA.htm
a load more here but not what i was looking for
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