4 replies to this topic

[Seema Sanal]

Hi All,

I have been working in a fishery processing factory. I would like to know any titration method or some other method for checking the salinity in finished product. salinometer used gives the salinity of the soaking solution only. please suggest some methods.

[Simon]

Can anyone help Seema with this?

Thanks,
Simon

[trubertq]

I have a procedure somewhere that I used for marinated herring, I will root it out for you.

It was an AOAC method using silver nitrate titration.
AOAC 937.09


3.4.3 Salt determination
Salt content was determined by the volumetric method of Volhard (AOAC 937.09 1990). 5 g of sample were weighed into a conical flask and 200 ml of distilled water added. The flask was placed on an electric shaker for 45 minutes. Then 20 ml of the solution was poured into an Erlenmeyer flask and the chloride ions precipitated by adding 10 ml of 0.1 N AgNO3. The excess AgNO3 was titrated with 0.1 N NH4SCN solution, a ferric indicator (FeNH4 (SO4)2*12H2O in diluted HNO3) was added for determination of the end point, when a fair red brownish colour appeared. The salt content was calculated as a percentage of the sample.
MmolCl/l= (B-S)*NNH4SCN*1000
Volume of sample
B= ml titrant for blank
S= ml titrant for sample
%Nacl= mmolCl/l*0.2L*58,5g/mol*0,001*100
gr sample

Edited by trubertq, 07 November 2012 - 10:26 PM.

[Seema Sanal]

I have a procedure somewhere that I used for marinated herring, I will root it out for you.

It was an AOAC method using silver nitrate titration.
AOAC 937.09


3.4.3 Salt determination
Salt content was determined by the volumetric method of Volhard (AOAC 937.09 1990). 5 g of sample were weighed into a conical flask and 200 ml of distilled water added. The flask was placed on an electric shaker for 45 minutes. Then 20 ml of the solution was poured into an Erlenmeyer flask and the chloride ions precipitated by adding 10 ml of 0.1 N AgNO3. The excess AgNO3 was titrated with 0.1 N NH4SCN solution, a ferric indicator (FeNH4 (SO4)2*12H2O in diluted HNO3) was added for determination of the end point, when a fair red brownish colour appeared. The salt content was calculated as a percentage of the sample.
MmolCl/l= (B-S)*NNH4SCN*1000
Volume of sample
B= ml titrant for blank
S= ml titrant for sample
%Nacl= mmolCl/l*0.2L*58,5g/mol*0,001*100
gr sample

[Seema Sanal]

Thank you very much for the information. This will help me a lot.

regards
Seema