1)why use benzophenon,uracil in hplc calibration.
2)why use sucrose in polarimeter calibration.
3)what is S/N ratio, noise and drift in hplc
4)how we can find lod and loq in method validation

Answer Posted / sri krishna

1. URACIL & BENZOPHENONE are commonly available standards,
with simple mobile phase i.e acetonitrile & water they can
be separated, peak shape is good, retension time is very low.
2. Sucrose is optically active which shows linearity1. Very
Easily prepared, Has a fixed rotation value which can
calibrated with 10%, 20% and 30% sugar value, and remains
constant for those concentration for a little time only,
upto that we can have a very sharp reading calibration of
pure sugar, Mainly polarimeter is used sucrose quality
detection for calibration with pure sucrose is the best
deal, Its shows almost no Muta rotation,And last and
final...Its most cheap to figure out and get the calibration
done.
3. signal to noise ratio. where signal is the response of
the analyte and noise is the disturbance present in the base
line.drift is the slow increase/ decrease the base line.
4.LOD: BY 7.1. Based on Visual Evaluation
Visual evaluation may be used for non-instrumental methods
but may also be used with instrumental methods.
The quantitation limit is generally determined by the
analysis of samples with known concentrations of analyte and
by establishing the minimum level at which the analyte can
be quantified with acceptable accuracy and precision.
7.2. Based on Signal-to-Noise Approach
This approach can only be applied to analytical procedures
that exhibit baseline noise.
Determination of the signal-to-noise ratio is performed by
comparing measured signals from samples with known low
concentrations of analyte with those of blank samples and by
establishing the minimum concentration at which the analyte
can be reliably quantified. A typical signal-to-noise ratio
is 10:1.
7.3. Based on the Standard Deviation of the Response and the
Slope
The quantitation limit (QL) may be expressed as:
QL = 10 σ/S

where σ = the standard deviation of the response
S = the slope of the calibration curve


Is This Answer Correct ?    14 Yes 1 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

sop of a uv visible spectrophotometer double beam elico model

5363


mahagenco syllabus for the post of chemist

5746


what is the principle involved in turbidometry and nephelometry ?

3640


How we can identify process related and degradation impurity in single method with short period?

340


If inhouse hplc related substance method is completly diffrent from Usp for finished proďuct with diffrent impurities then how require to prove method equivalecy?

322






process of Diclofenac sodium,IP.

1681


What is intact assay method development.....?

2010


why we use glass fiber filters use in some situation?

328


why glutent are detected in the rice cereal baby food product even manufacturer claimed that they are using rice and milk only?we have using ELISA to do the test,and rice supposed not containing any glutent,rite?We already repeat the test so many times and it still detected.just wondering where the glutent came from?

2350


please explain about aluminium hydroxide assay

713


why lactose has less charges when packed in steel containers when compared with packing of lactose in polyamide material?

1772


What should be the level/ Percentage of Arsenic in Arsenic free zinc.

1768


How do we get end points and how many end points are possible for citric acid and di-acid not theorotically answer should be given practically.

2060


I have compare C2H2-air and C2H2-N2O flame AAS on determination calcium. Both use same range of std to plot calibration curve. (2-6ppm) When i measure the sample with phosphate, KCl and LaCl, C2H2-N2O flame give false positive result, around 0.5ppm. When i measure the sample with phosphste, KCl and EDTA. C2H2-N2O flame also give 0.5ppm false positive. But both above mentioned sample would not give false positive when measured by C2H2-air flame. What is the reason?

2984


pharma industries oriented

1692