Balances and Micropipettes

1
Balances and Micropipettes

• By Paola Restrepo and Ankita Desai

2
Balances

• Types
• Micro balances
• Top Loaders
• Analytical Balances
• Floor Scales

3
Validation

• Pre-purchase meeting with QA, users, and a member
  of Metrology
• Discuss the user requirements and the suitability
  of the proposed balance to be purchased.
• The Lab Strategy form is completed once the
  equipment arrives to determine whether it will be
  used for GXP purposes.
• If the unit is to be validated, protocols are
  drafted, reviewed and approved by the user and
  the validation team. Example of protocols
  include the Installation Qualification and
  Operational Qualification.
• Additional task include
• The calibration/maintenance requirements to be
  performed periodically.
• Users and Metrology will create or revise any
  SOPs (use/calibration).
• Once all of the pertinent documents and tasks are
  executed, reviewed, and approved (meets all
  specifications), the balance may be release for
  GXP laboratory purposes.

4
(No Transcript)
5
Calibration

• All of the calibration requirements (determined
  during the validation phase) are setup in the
  validated software database referred to as
  Calibration Manager.
• The database information
• Includes the location of the equipment, user
  department, cost of unit, history (calibration,
  unscheduled repairs, etc.), scheduling, and
  calibration data references.
• Calibration scheduling may include monthly,
  quarterly, and semiannual checks.

6
(No Transcript)
7
How its done?

• The monthly checks may require minimum and
  maximum weight checks.
• The monthly uncertainty is checked using the min
  weights.
• Additional maintenance is done as required.
• The semiannual calibration checks may involve the
  use of an approved outside vendor to perform
  calibrations and maintenance
• Includes lubing and thorough cleaning.

8
Accuracy

• Accuracy Checks are done using calibrated Class 1
  weights.
• During Calibration
• Min/Max /- 0.1 (measured vs. certified)
  Uncertainty /- 0.1 (repeat of 10 measurements
  of the min)
• Daily Activities
• Min /- 0.1 (measured vs. certified)

9
Weights

• The weights are calibrated by a certified vendor.
  
• Solvay sends their weights to Heusser Neweigh.

10
(No Transcript)
11
Daily Use

• Users perform daily checks using the minimum
  weight accepted on the balance. This is required
  before the balance may be used for any GXP
  purposes that day.
• The daily accuracy specification is the certified
  minimum weight vs. the measured minimum weight
  /- 0.1 of the weight.
• The daily checks along with any other entries
  such as the material to be weighed are recorded
  in the logbook.
• The logbook is cross referenced with the lab
  notebook.

12
Micropipettes

• Micropipettes are used to transfer small liquid
  volumes.
• It is used for more accurate and precise
  measurements of volumes smaller than 1ml.
• It was invented in 1957 by Heinrich Schnitger in
  Germany.

13
Micropipettes

• Micropipettes have 3 positions
• Rest position.
• First stop.
• Second stop.
• How to use it
• Set volume.
• Attach disposable tip.
• Depress the plunger to 1st stop.
• Immerse tip in sample and Draw up sample.
• Withdraw the tip.
• Dispense the sample by pushing the plunger to the
  2nd stop.
• Withdraw the pipette and release the plunger.
• Discard the tip

14
Accuracy and precision

• Optimal range 35 - 100 of volume
• Use a correct immersion angle. Pipette
  perpendicular to solution.
• Withdraw tip slowly and smoothly from liquid.
• Maintain controlled aspiration rates. Dont let
  plunger snap back.
• Be consistent with pipetting rhythm, pressure on
  the plunger and speed.

15
Micro Pipettes

• The pipettes are purchased based on the users
  preference.
• Solvay Pharmaceuticals typically purchases from
  Eppendorf.
• Standard pipettes are not validated (IQ/OQ)
• Calibrated on a semiannual basis

16
Calibration

• Solvays calibration is currently done by
  Troemner
• Troemner has been audited and deemed as an
  acceptable vendor to calibrate them.
• They do As Found (when received or as is) and
  As Left (after adjustments/maintenance).

17
(No Transcript)
18
References

• http//us.mt.com/home
• http//en.wikipedia.org/wiki/Micropipette
• Solvay Pharmaceuticals