why 0.005 M sulphuric acid is used to calbrate spectrophotometer and why caff

why 0.005 M sulphuric acid is used to calbrate
spectrophotometer and why caffiene is used for calibrating
hplc

Question Posted / latha

2 Answers
22192 Views
GVK, Torrent Pharma, I also Faced
E-Mail Answers

Answers were Sorted based on User's Feedback

why 0.005 M sulphuric acid is used to calbrate spectrophotometer and why caffiene is used for cal..

Answer / kanakadurga

A solution of 0.005M H2SO4provides ionic strength to the
solution (hence, it changes the refractive index so as to be
similar to comparable solutions), but it doesn't absorb much
in the UV or Visible region. Therefore, light hitting the
detector will be almost all stray light.

Caffine is primary standard and Shows maxima at two
different wavelength ie.205nm & 273nm and Cheap & easily
available

Is This Answer Correct ?

19 Yes

0 No

why 0.005 M sulphuric acid is used to calbrate spectrophotometer and why caffiene is used for cal..

Answer / sp goswami

A 0.005M sufuric acid solution gives the required ionic
strength, required dissolution and also do not interfere in
UV-VIS Region giving 99% absorbance for the analyte of
interest so 0.005 M diluted sulfuric acid is useful .
Caffeine is a primary std ,pure form ,good absorbance and
readily available in market
Regards

Is This Answer Correct ?

10 Yes

3 No

Post New Answer

More Analytical Chemistry Interview Questions

What is the reason of RT change in new column v/s old column in HPLC

3 Answers Apex,

how to hplc calibrated

4 Answers Dr Reddys, Glochem,

how do we get usp reference standard potency?

1 Answers Ind Swift Laboratories, MSN Pharma,

What is difference between silica used in TLC and HPLC column

4 Answers Cipla, Meghmani Organics,

How to choose Normal phase or Reverse Phase HPLC method Conditions for given sample?

3 Answers PharmaZell,

What is the function of end capped column?

5 Answers Cipla,

How we will choose pH of a mobile phase if analyte pKa value is 4

2 Answers Celon Labs, Laurus,

Why pH range is maximum 14.0

6 Answers UPL,

Optical Rotation*0.9477*100*200] Assay Of dextrose= ________________________________ 99.8* 200 why Factor=0.9477

1 Answers Claris Lifesciences, Inven Pharmaceuticals, Levo,

stability study is going on up to 3years for famotidine-USP but the pharmacopeia is revised and tlc test is replaced with hplc test. At the 4th year frequency the product is failed in hplc test .how can i assain the expiry or retest date and can i stop or continue the programme?

2 Answers Nakoda Chemicals,

why r u using hplc grade solvents

4 Answers

Why use only methanol,used determinationof moisture content not use other solvents

0 Answers

For more Analytical Chemistry Interview Questions Click Here