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3DJH RI
4.3)
Precision:
4.3.1) Definition:
The precision is a measure of the closeness of agreement between observed
values obtained independently from multiple samplings of a homogenous sample and is
expressed as the variance, standard deviation or relative standard deviation (coefficient of
variation) of observed values.
4.3.2) Assessment for Area:
Determined by injecting 5 different concentrations of standards 5
times each and 7 different samples 2 times each and calculating the relative standard
deviation (RSD).
4.3.3) Assessment for Retention Time:
Checking the relative standard deviation of retention
time of the peaks obtained using the above solutions.
4.3.4) Assessment for reproducibility of result:
By analyzing the same sample in duplicate
and finding the relative standard deviation of the assay.
4.3.5) Acceptance Criteria:
The Relative standard deviation to be less than 2.5% for all the
above.
4.3.6) Precision for peak areas:
Experiment:
a) Standard preparation: Prepared as mentioned in linearity 4.2.4 (a).
b) Sample preparation:
The sample solution was prepared by weighing the quantity of
the sample shown in the
Table
in a 250 ml beaker, extracted with 100ml of methanol,
boiling on water bath for 10-15 minutes and repeated the procedure 3-4 times till the
material is completely extracted or till the extracts turn colourless. Combined all the
fractions, concentrated and made up the volume to 50ml with methanol. Filtered
through 0.45 microns membrane filter paper.
Table -17
Batch No.
Quantity (mg)
753.6
1503.2
WS/06Lot10
2096