electronic balance uv-visible spectrophotometer

1. Qualification of analytical
instruments: Electronic
balance,
UV-Visible
spectrophotometer
Submitted by
Pattan Sohail
M pharm 1st year

2. • Validation of an analytical procedure is the process
by which it is established, by laboratory studies, that
the performance characteristics of the procedure
meet the requirements for the intended analytical
applications.” (Definition of Validation: USP)
• Qualification is part of validation but the individual
qualification steps alone do not constitute process
validation
• Qualification deals with components or elements
of a process
• Validation deals with the entire manufacturing
process of a product

3. QUALIFICATION OF BALANCES
“Qualification of Equipment”, which together should
be used when planning, performing and
documenting the qualification process of balances
• The core document contains the introduction and
general forms for Level I and II of qualification, which
are common to all types of instruments.

4. AIM AND SCOPE OF THE GUIDELINE
This guideline describes the requirements for balances
(electronic - digital) used in chemical and biological
tests in OMCLs. The following types of balances are
considered in this guideline
Type Ordinary name No.of digits after
decimal
position(g)
Accuracy class
1. Ultra micro
balance
7 I
2. Micro balance 6 I
3. Semi-micro
balance
5 I
4. Analytical balance 4 I
5. Precision balance 1 TO 3 II
6. Technical balance 0 TO 1 III

5. CONSIDERATIONS FOR LEVEL I AND II OF
EQUIPMENT:
QUALIFICATION At Level I of the qualification of
balances (selection of instruments and suppliers), it
is recommended to select a manufacturer of
balances that can satisfy the needs of the laboratory
and works under ISO 9001 certification. At Level II of
the qualification of balances (installation and release
for use), it is recommended to check all the
requirements set during the selection of the
instrument and calibration should be performed
before putting into service by an accredited external
service supplier, or internally by appropriately
qualified personnel, using certified reference weights
according to an approved procedure.

6. 4. REQUIREMENTS FOR BALANCE USE
Location of the Balance
The accuracy and precision of weighing
results are closely associated with the location of the
balance. OMCLs should ensure that the balance can
work under optimal conditions (weighing
room/laboratory, weighing bench, temperature,
light, air, etc,.)
• It should be ensured that the weighing bench is
stable, no matter from what material it is made. The
weighing bench should not deform when work is
carried out on it and it must be vibration-proof or the
transfer of vibrations must not influence the
weighing process.

7. Temperature
As weighing results are influenced by temperature,
OMCLs should ensure a constant temperature is
maintained in weighing rooms/laboratories. The
deviation should not exceed more than 5 °C per hour.
Atmospheric humidity
The optimum relative humidity (% RH) during a
weighing process is between 40 % to 60 % 80 % in
cases where the accuracy and linearity of
measurements are not affected. Light Balances
should be protected from direct sunlight (heat).
Air
OMCLs should not place balances in the airflow of air
conditioners or devices with ventilators next to
doorways or in areas of high traffic.

8. Weighing vessel
OMCLs must ensure that:
- the smallest possible weighing vessels are used.
- if the materials that the weighing vessel is made of
have a high degree of electrical insulation they are
not electrostatically charged.

9. FREQUENCY OF QUALIFICATION
OMCLs must ensure that qualification/calibration of
balances is done on receipt (i.e. immediately after
delivery) or prior to their first use and after any
repair or move.
The frequency of qualification/calibration depends
on the extent of use of the balances and is at the
discretion of individual OMCLs.
Qualification/calibration must be performed in
accordance with a pre-determined protocol in which
acceptance criteria are defined
• k = correlation coefficient
• SD = standard deviation
• RSD = relative standard deviation

10. Parameter to be checked Frequency Typical tolerance limit
Levelling Every day before weighing
begins
Acceptance limits of the
balance
Internal caliberation Every day before weighing
begins
Automatic acceptance
limits of the balanc
Verification Atleast once a week OMCLs shall define their
own acceptance criteri.
Accuracy Frequency to be defined
by OMCL,typically once a
year
OMCLs shall define their
own acceptance criteri.
Linearity Frequency to be defined
by OMCL,typically once a
year
OMCLs shall define their
own acceptance criteri.
(k= 1±0.0001)
Precission Frequency to be defined
by OMCL,typically once a
year
OMCLs shall define their
own acceptance criteri.
(SD=max 5*d)
Eccentricity Frequency to be defined
by OMCL,typically once a
year
OMCLs shall define their
own acceptance criteri.
(RSD=0.05%)

11. Verification
Verification of the balance is performed by placing a
suitable weight in the centre of the weighing pan
once and comparing the result with pre-defined
acceptance criteria. The same weight should always
be used in these verifications. The acceptance
criteria shall be defined by each individual OMCL.
Accuracy
The accuracy of the balance is checked by weighing
at least three different certified weights that cover
the usual weighing range of the balance. It is
recommended that the weights have approximately
5%, 50% and 100% of the maximum capacity of the
balance depending on the type of balance. It is
recommended that the weighing is repeated at least
5 times for every weight.

12. Linearity
The results obtained from a series of accuracy checks can
be used to calculate the correlation coefficient and to
check for linearity. The correlation coefficient is
calculated by comparing the nominal and measured
masses of the weights. The acceptance criteria for the
correlation coefficient shall be defined by each individual
OMCL.
Precision
The precision of the balance should be verified by
weighing at least 5 times a weight that is equivalent to
approximately 50% of the maximum capacity of the
balance. It is recommended to repeat the test with a
weight that is equivalent to approximately 5% of the
maximum capacity of the balance, if the balance is used
at the lower range (Proposed criterion: SD = max 5*d,
where d = (actual) scale interval (e.g. d=0.1 mg).

13. CALIBRATION OF UV-VISIBLE
SPECTROPHOTOMETER
Tests Performed In UV-Visible
Spectroscopy:
 Baseline flatness test
 UV region wave length accuracy test
 Visible region wave length accuracy
test
 %Transmittance of Cuvette
 Control of absorbance
 Emission lines from deuterium
discharge lamp
 Stray Light measurement
 Resolution power
 Photometric linearity

14. Make,
Soft ware
& Version
Model
type &
Serial No
Beam
type
(single/d
ouble)
INS/
EQP.ID
No.
SOP No Calibratio
n
Frequenc
y
Every six
months
Instrument/Equipment Calibration Record
INS/ EQP Name: UV-VISIBLE spectrophotometer
Department Name: Central Instrumentation Lab
Equipment Details:

15. 1) Baseline Flatness Test:
Measurement configuration parameters:
Reference : No Cuvette
Sample : No Cuvette
Cuvette material : Quartz
Wave length range : 200-800
Lamp : Deuterium lamp
Detector : PDA detector

16. WAVE LENGTH MEASURED ABSORBANCE ACCEPTANCE CRITERIA
200 ±0.001
300 ±0.001
400 ±0.001
500 ±0.001
600 ±0.001
700 ±0.001
800 ±0.001

17. 2) Uv Region Wave Length Accuracy Test:
Measurement configuration Parameters
Reference : Air (Empty Cuvette)
Sample : Benzene
Recording range : 220-270nm
Lamp : Deuterium Discharge
Detector : PDA Detector
WAVE LENGTH (nm) OBSERVED PEAKS AT
WAVE LENGTH (nm)
ACCEPTANCE CRITERIA
220-270 nm 235.9±0.5nm

18. 3) Visible Region Wave Length Accuracy Test:
Measurement Parameters:
Reference : Distilled Water
Sample : 0.01% KMno4
Measuring mode : 300 to 600nm
Lamp : Deuterium
Discharge Detector : PDA Detector
WAVE LENGTH (nm) OBSERVED PEAKS AT
WAVE LENGTH(nm)
ACCEPTANCE CRITERIA
300-600nm 310±1nm
525±1nm

19. 4) %Transmittance Of Cuvette:
Measurement configuration Parameters
Reference : Empty Cuvette
Sample : Empty Cuvette
Cuvette material : Quartz
Measuring mode : 240nm
Lamp : Deuterium discharge lamp
Detector : PDADetector
WAVE LENGTH(nm) %TRANSMITTANCE ACCEPTANCE
CRITERIA
240nm Not less then 80%

20. 5) Control of absorbance:
Absorbance:Visible region
 Place dummy Cuvette in sample holder and set %T to
“zero”. Now remove dummy Cuvette, by using fine & coarse
control set a reading exactly 40.0 on the read out. Press
Absorbance push button. If the maximum absorbance
obtained at λ of 485nm is 0.398 ± 0.002, the photometric
calibration of instrument is confirmed to be proper.
 To confirm, repeat above steps, and set 10.00 on read out
 Press Absorbance button. If the λ at 485 nm is 1.000±0.002
then it is confirmed the photometric performance in the
visible region is proper.
Absorbance:U.V region
Place blank0.1N H2SO4 Cuvette and 60ppm K2Cr2O7 as
sample
Set λ exactly to 257 nm, if the value of Absorbance of
sample at the set λ is 0.864±0.005, the instrument is
measuringAbsorbance properly.

21. 6) Emission Lines From Deuterium Discharge Lamp:
Measurement configuration Parameters:
Reference : No Cuvette
Sample : Empty Cuvette
Recording range : 400-500, 600-700
THEORETICAL
VALUE
OBSERVED
VALUE
DIFFERENCE ACCEPTANCE
CRITERIA
486nm 486±0.3nm
656nm 656±0.3nm

22. 7) Stray Light measurement:
 Weigh accurately 1.2g of dried Potassium chloride in
100 ml volumetric flask and makeup to mark with
Double distilled water.
 Measure the absorbance at 200 nm.
Acceptance criteria: Tolerance limit NLT 2.0
8)Resolution Power:
 Prepare 0.02%v/v solution of Toluene and make up
with Hexane.
 Scan the wavelength from 250 to 280nm.
 Maximum absorbance is 269 nm and Minimum
absorbance is 266nm
 Acceptance criteria: Ratio limit NLT 1.5

23. 9) Photometric linearity:
 Weigh accurately 100mg of Potassium chromate in
100ml volumetric flask and dissolve in 0.05N
Potassium hydroxide solution. Make up with the
same solvent.
 From the above solution take 20ml and make up
to 500ml with 0.05N Potassium hydroxide solution.
 Now prepare dilution of 4,8,16,24,32 µg/ml.
 Measure the absorbance at 370nm using blank.
Acceptance criteria: The plot should be linear and
regression coefficient (R2) should NLT 0.999.