Calibration of UV / Visible spectrophotometer

Calibration of UV / Visible spectrophotometer

OBJECTIVE:                                                                                                                      

To provide a procedure for calibration of UV / Visible spectrophotometer.

SCOPE: 

Applicable to the Spectrophotometer in Quality Control Department.

Model    : UV-1700, Pharmaspec.

Manufacturer : Shimadzu Corporation.

RESPONSIBILITY:

Chemist.

PROCEDURE:

Ensure that the connections of the instrument are proper.

Control of Absorbance

Potassium dichromate Solution :

Dry a quantity of potassium dichromate by heating to constant weight at 130°C. Weigh & transfer accurately a quantity not less than 57.0 mg & not more than 63.0 mg to 1000 ml volumetric flask.   Dissolve & dilute in sufficient 0.005M H₂SO₄ to produce 1000 ml.

Measure the absorbance of potassium dichromate solution at the wavelengths given below.

Calculate value of A (1% 1cm) for each wavelength.

A (1% 1cm) = Absorbance X 10000 / Weight of Potassium dichromate in mg.

Acceptance criteria

Wavelengths (nm)	A [1% 1cm]	Limit
235.0	124.5	122.9 - 126.2
257.0	144.0	142.8 - 145.7
313.0	48.6	47.0 - 50.3
350.0	106.6	105.6 - 108.2

Stringent limits are adopted from IP & BP for acceptance criteria

Resolution power

Record the spectrum of a 0.02% v/v solution of toluene in hexane in the range of 260 nm to 420 nm (before use check the hexane for transmittance, using water as a blank between 260nm to 420nm & use only if transmittance is not less than 97%).

Acceptance criteria:

The ratio of the absorbance at the maximum at about 269nm to that at the minimum at about 266nm is not less than 1.5.

Limit of Stray Light

Prepare a 1.2 % w/v solution of Potassium chloride in water.

Measure absorbance of the above solution at  198.0,199.0,200.0,201.0,202.0 nm using water as blank.

Acceptance criteria:

Absorbance is greater than 2.

Wavelength accuracy, Resolution & Baseline flatness (inbuilt test)

Attach printer directly to the instrument (instead of computer).

Go to Þ MODE press F3 key i.e. Maintenance.

Press ‘1’.

Press Start/Stop key.

After screen changes, ensure that nothing is kept in the optical path & press the Start/Stop key again.

Prints will come after all the three tests are over.

Acceptance criteria:

For wave length accuracy : at 656.1 ± 0.3 nm & at 486.0 ± 0.3 nm.

Resolution: 1.0 nm or less.

Baseline flatness: ± 0.002Abs.

Frequency

Once in a month.

Maintenance / Repairs

When the instrument does not comply with the requirement / tolerance range specified above, the instrument should be labeled “OUT OF CALIBRATION” and should be repaired / serviced.

After repair / maintenance, calibrate the instrument.

REFERENCE

Indian Pharmacopoeia

British Pharmacopoeia

Instruction manual of UV-1700.

CALIBRATION REPORT OF UV / VISIBLE SPECTROPHOTOMETER Page 1 of 2

SOP Reference –

Date -

Instrument No. – EH/QCD/

Frequency

: Once in a month

Make –

Model –

1.

Control of Absorbance: Potassium dichromate solution : Gross Wt. :  ………………….                                 Balance : EH/QCD/ Tare Wt. :  …………………. Net Wt.    : ………………….                                        ………..           ml with 0.005M sulphuric acid. Dissolve and dilute 57.0 to 63.0 mg of potassium dichromate in sufficient 0.005M sulphuric acid to produce 1000.0 ml.

Wavelength (nm)

Absorbance

A (1%, 1cm)

Tolerance

235.0

122.9 to 126.2

257.0

142.8 to 145.7

313.0

47.0 to 50.3

350.0

105.6 to 108.2

Calculation :

1%                    Absorbance  x 10000

A1 cm    = -------------------------------------------------------

Weight of potassium dichromate in mg Remark : Satisfactory / Not satisfactory.

Performed by : Date :

Checked by : Date :

2.

Resolution power : 0.02% v/v toluene in hexane :               ……….ml   ® 100.0 ml with hexane  / ………  ml   ® 100.0 ml with hexane Absorbance at 269 nm = …………… Absorbance at 266 nm = ……………                           Absorbance at 269 nm                 Ratio = ---------------------------------- =    ---------------- =                           Absorbance at 266 nm                                (Limit : Not less than 1.5) Remark : Satisfactory / Not satisfactory. Performed by :                                                                 Checked by: Date :                                                                                Date           :

CALIBRATION REPORT OF UV / VISIBLE SPECTROPHOTOMETER Page 2 of 2

3.

Limit of stray light:

Potassium chloride solution Gross Wt.                :  ………………….                                  Balance : EH/QCD/                            Tare Wt. :  …………………. Net Wt.    : ………………….                          ……………. ml with water. Dissolve and dilute accurately 1.2 g potassium chloride  in sufficient water to produce 100.0 ml.

Sr. No.

Wavelength (nm)

Absorbance

Tolerance

1

198.0

Absorbance is greater than 2

2

199.0

3

200.0

4

201.0

5

202.0

Remark : Satisfactory / Not satisfactory.

Performed by : Date :

Checked by : Date :

4.

Wavelength accuracy (In built test)

Sr. No.

Wavelength Standard (nm)

Wavelength Observed (nm)

Difference

Limit (nm)

1

656.1

+ 0.3

2

486.0

+ 0.3

Remark : Satisfactory / Not satisfactory. Performed by :                                                                 Checked by: Date :                                                                                Date           :

5.

Resolution (In built test)

Sr. No.

Limit

Observation

1

1.0 nm or less

nm

Remark : Satisfactory / Not satisfactory. Performed by :                                                                 Checked by: Date :                                                                                Date           :

6.

Baseline flatness (In built test)

Sr. No.

Limit

Observation

1

± 0.002 Absorbance

Remark : Satisfactory / Not satisfactory. Performed by :                                                                 Checked by: Date :                                                                                Date           :

Conclusion : Instrument working is Satisfactory / Not satisfactory.

Next calibration due on :

Performed by : Date :

Checked by : Date :