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Water by KF_result_w/w

Posted: Mon Feb 14, 2011 9:12 am
by mohammad
Dear All,

I am doing water content of ciprofllxacin by KF instrument.
using the formula :
TV x factor of KF (mg/ml) x 100 / weight of sample in (mg).

Genrally we are giving the result as %(w/w).

But how are we getting to this conclusion?

Can any 1 explain.

Regards
Mohammad.

Re: Water by KF_result_w/w

Posted: Mon Feb 14, 2011 10:35 am
by krickos
Hi

Unless I misunderstood the question the equation is quite straight forward.

TV=Volume of KF reagent used to complete the titration in ml
F= factor of KF solution in mg/ml
m= weight of sample in mg.
100=coversion to %

So the volume of KF reagent used times the factor is directly proportional to the amount of water in your sample.

Re: Water by KF_result_w/w

Posted: Mon Feb 14, 2011 8:04 pm
by mohammad
hai,

can you explain y we are mentioning (w/w) along with (%) for solid samples........

regards
mohammad

Re: Water by KF_result_w/w

Posted: Mon Feb 14, 2011 9:16 pm
by tom jupille
"w/w" means "weight divided by weight". That is redundant for solid samples (which would not be "w/v" or "weight divided by volume") but it is better to be redundant and repeat your self than it is to be incomplete.