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Cleaning and purity modifide

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Pradeep Kumar
Pradeep Kumar

Glassware cleaning and the purity of reagents and gases are important for parts per billion level analysis using chromatography. Basic steps for cleaning glassware include washing with tap water, a cleaning agent, tap water again, distilled water, and drying at room temperature or in an oven. The purity of chemicals, reagents, and gases used needs to match the sensitivity of the analytical technique, and purity can be checked using reagent blanks. Solvents may need purification through redistillation using an all-glass apparatus, while gases for chromatography require ultra high purity levels of 99.999% or higher.

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GLASSWARE CLEANING, PURITY OF REAGENTS AND GASES Pradeep Kumar. G.T
Importance of cleaning • Parts per billion range analysis • Carefully clean glassware is mandatory. • Extraneous peaks in chromatograms • Difficult interpretation
Basic steps • Wash glass ware with tap water • Wash with cleaning agent • Wash with tap water • Cont.
•Rinse with distilled water •Dry at room temperature •Oven drying and storage
Cleaning and purity modifide
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.
Grades • The grade indicates how pure the chemical is –Guaranteed Reagent (GR) or AR –HPLC grade –Pesticide Residue
Purification • Purification required on finding any contamination in reagent blank. • Purification includes distillation, high temperature treatment etc.
• 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.
PURITY OF GAS • Ultra High Pure Gas for Gas Chromatography. • Commercial nitrogen gas
• 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.
Cleaning and purity modifide

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Cleaning and purity modifide

  • 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.