LS_CHT_BIA_L33_Ltr14_Maintenance in FAAS and ICP-OES

Lesson Overview

• Lecture 14: Maintenance in FAAS and ICP-OES

• Basic Instrumental Analysis

• Module Code: LS5006FPR/LS5012FP

Learning Objectives

• Understand basic maintenance protocols in AAS and ICP-OES, covering:

  • Gas supply

  • Sample introduction system (nebulizer and spray chamber)

  • Burner or torch

  • Drain system (waste bottle)

Gas Supply Maintenance

• Gas Supply System:

  • Gas supplied through piped systems and rubber hoses.

  • Regularly check connections for leaks, especially when tank changes occur.

  • Utilize soap solution or leak detectors.

• Contaminated Air Effects:

  • Noise in results may stem from contaminated air.

  • Air filter essential for metal analysis.

  • Inspect air filter for particle and moisture accumulation; clean if necessary.

Sample Introduction System: Nebulizer

• Components:

  • Comprises capillary tubing and nebulizer body.

  • Check for depressions/plaque on tubing; ensure proper fit to avoid air leaks.

• Clogging Issues:

  • Clean nebulizer using ultrasonic method with 0.5% liquid soap for 10 mins.

  • If clog persists, use a burr-free nebulizer wire followed by ultrasonic cleaning.

Sample Introduction System: Spray Chamber

• Inspection and Cleaning:

  • Inspect glass bead when removing nebulizer; check for cracks and breakage.

  • Clean spray chamber and liquid trap using detergent and warm water; rinse with distilled water and dry.

Maintenance in AAS - Burner

• Salt Accumulation Reduction:

  • To minimize salt buildup, aspirate a dilute acid solution between samples.

  • Clean using a brass cleaning strip without sharp objects to avoid damaging the slot.

  • Soak burner in warm soapy water; thoroughly rinse and dry before reinstalling.

  • Run 50-100 ml of distilled water through after sample measurement each day.

Maintenance in AAS - Lamps

• Lamp Condition:

  • Check hollow cathode lamps for deposits; replace if necessary.

  • Optical Path:

    • Inspect for dust; clean using lint-free cloth or appropriate materials.

  • Alignment & Calibration:

    • Check optical alignment and perform spectral calibration using reference materials.

Maintenance in ICP-OES - Air Filter

• Filter Maintenance:

  • Located on sides/rear of instrument; can be cleaned with vacuum or air.

  • Chiller Maintenance:

  • Maintain coolant levels; check filters and pressure. Do not use water; follow vendor recommendations for coolant.

Maintenance in ICP-OES - Torch

• Torch Inspection:

  • Look for cracks or damage in quartz tube; remove deposits by soaking in warm soapy water.

  • Rinse with distilled water before reinstallation.

  • Aspirate distilled water or a blank solution post-analysis.

Maintenance in ICP-OES - Injector

• Injector Maintenance:

  • Clean injectors to avoid clogging; soak in ultrasonic bath with soapy water or aqua regia for heavy deposits.

  • Rinse and dry thoroughly; for organics, clean with solvent or dilute nitric acid solution.

  • Alternatively, use a muffle furnace at 500-550°C.

Maintenance in ICP-OES - Nebulizers

• Post-Analysis Cleaning:

  • Aspirate 5-10% nitric acid followed by DI water for 15 minutes each.

  • For aggressive cleaning, soak in 5-20% nitric acid or aqua regia, then rinse with DI water.

Maintenance in ICP-OES - Peristaltic Pump and Tubing

• Pump Maintenance:

  • Minimal maintenance needed; clean rollers if liquid spills occur.

  • Tubing Replacement:

  • Replace tubing frequently; daily changes recommended for sample and internal standard tubing.

  • Ensure chemically compatible tubing is used.

Drain System - Waste Bottle

• Maintain liquid level to ensure proper back pressure for nebulizer gas flow.

• Conduct daily checks and frequent disposal; use only wide-necked bottles for waste collection.

Preventive Maintenance

• Consider comprehensive preventive maintenance services from manufacturers or qualified technicians.

• Services may include checks/calibrations of various parameters, replacement of worn components, and ensuring optimal performance.

  • Calibration Tasks:

    • Spectral calibration using certified reference materials.

    • Thoroughly check and recalibrate optical alignment and detector accuracy.

References

• Routine maintenance for FAAS application note, Agilent Technologies.

• Instrument Care and Maintenance, PerkinElmer.