Checklist for Precautions during working on Analytical Weight Balance (Before weighing)

ABHA

Checklist for Precautions during working on Analytical Weight Balance (Before weighing)

Checklist for Do’s

  • Check calibration of balance before  weighing
  • Always ensure that the spirit level of the analytical balance is proper.
  • Check silica gel for activation (dark blue) if not then dry it in the Oven till the color changes to dark blue.
  • Use a cleaned balance for weighing if not then clean it with a brush.
  • Check direct current to balance, and put off the AC if necessary to avoid fluctuation in the recording of weight during weighing.
  • The balance should be  placed on the vibration-free table
  • Weigh material that has attended the laboratory temperature.
  • Before weighing Check the maximum capacity of weighing.
  • During weighing check the position of the balance pan & should be in contact with the balance spring.
  • Always Weigh in the center of the pan
  • During the recording of weights, close all the doors properly & record weight only after stabilization.
  • If the fluctuation is observed in the recording of weight, even after switching off the AC, call the service engineer
  • Weigh corrosive material, liquid material, or semi-solid material in glassware taking into care maximum capacity.
  • Transfer weighing material in labeled Glassware/apparatus to avoid analysis errors.
  • During analysis always use personal protective equipment e.g. gloves, nose mask, etc.
  • In case of liquid weighing, transfer some material to another container and use that for weighing.
  • Use a clean spatula for weighing
  • After weighing discard the excess material which is taken from the original container.
  • If weighed wrong, discard it
  • Always weigh within 10% of theoretical weight e.g. 50mg (Weigh between 45 to 55mg). Also should keep a minimum of 5 % weighing the difference between the two standards & sample preparation. If standard A weighed 50.00 mg then standard B should weigh around 52.5 mg & same for sample preparation for more accuracy.
  • Put off light for weighing of light-sensitive materials
  • Mix the content properly in case of tablet powder, capsule blend, and weigh powder equivalent to ____gm of active
  • Before using/weighing liquids, suspension, etc. For analysis, It should be shaken well.

Checklist for  Don’ts

  • Don’t use the balance for weighing without calibration
  • Do not use the balance if the spirit level is improper/not adjusted.
  • Don’t use deactivated silica gel in balance (Pink to white)
  • Don’t use the unclean balance for weighing.
  • Don’t on AC during weighing if the fluctuation is observed due to direct flow.
  • Don’t keep balance on a table that is not vibration free.
  • Don’t weigh cold materials, directly removed them from the fridge,  also don’t weigh hot materials like  LOD bottles, crucibles, etc.
  • Don’t exceed the maximum capacity of the balance
  • Don’t drop an object on the balance pan, it will affect the balance spring.
  • Don’t weigh it by keeping it on the outer side of the pan.
  • Don’t open the door during stabilization.
  • Don’t keep material for too long on the balance pan as a sample may lose or gain weight.
  • Don’t use balance if the fluctuation is observed during weighing.
  • Don’t use butter paper for weighing corrosive & semisolid material.
  • Don’t use unlabelled Glassware for analysis
  • Don’t perform analysis without using personal protective equipment
  • Don’t  contaminate the original liquid container by dipping the pipette
  • Don’t use an unclean spatula for weighing
  • Don’t put excess material back into the original container or do not contaminate the original container
  • Don’t continue analysis with wrong weighing
  • Don’t weigh above 10 % of the theoretical weight.
  • Don’t weigh the exact standard weight for duplicate standard/sample preparation.
  • For e.g. if the standard weight to be weighed is 50 mg then don’t weigh both standard 50.00 mg and 50.05 mg keep a 5% difference between both weighs.
  • Don’t put on light during the weighing of Light sensitive materials
  • Don’t use tablets, or capsules as such if mentioned in the specification to be crushed& weighed the powder.
  • Don’t use liquid & suspension as such for weighing/ analysis without shaking.

 

SOPs