1. GLASSWARE CLEANING,
PURITY OF REAGENTS
AND GASES
Pradeep Kumar. G.T

2. Importance of cleaning
• Parts per billion range analysis
• Carefully clean glassware is
mandatory.
• Extraneous peaks in
chromatograms
• Difficult interpretation

3. Basic steps
• Wash glass ware with tap
water
• Wash with
cleaning agent
• Wash with tap water
• Cont.

4. •Rinse with distilled
water
•Dry at room
temperature
•Oven drying and
storage

6. Purity of Chemicals, Reagents,
Solvents, Standards and Gases
• Purity is based on the sensitivity
and specificity of the analytical
techniques being used.
• Suitability of routine reagents is
documented through reagent
blanks.

7. Grades
• The grade indicates how
pure the chemical is
–Guaranteed Reagent (GR) or
AR
–HPLC grade
–Pesticide Residue

8. Purification
• Purification required on finding
any contamination in reagent
blank.
• Purification includes
distillation, high
temperature treatment etc.

9. • Solvents viz. hexane, chloroform,
toluene, isopropanol, methanol,
dichloromethane, ethyl acetate etc. can
be purified by redistillation using all-
glass apparatus.
• To remove phthalate esters that
interfere in determinations using
Electron Capture Detecter (ECD), heat
Na2SO4/NaCl for 4 hr in a muffle
furnace at 600oC.

10. PURITY OF GAS
• Ultra High Pure Gas for
Gas Chromatography.
• Commercial nitrogen gas

11. • Ultra High Pure Gas (UHP)
• purity ≥ 99.999% (Free from other
gas, moisture, hydrocarbons)
• Commercial nitrogen gas
• The minimum required purity is
96% to prevent oxidation and
other reactions.