Xylenol orange adsorbed on silica surface as a solid phase reagent for lead determination using diffuse reflectance...

Area of Science:

• Analytical Chemistry
• Materials Science
• Environmental Science

Background:

• Xylenol orange is a versatile indicator and chelating agent.
• Immobilizing reagents on solid supports enhances their reusability and stability.
• Lead (II) is a toxic heavy metal requiring sensitive detection methods.

Purpose of the Study:

• To develop and characterize novel solid-phase reagents for lead (II) pre-concentration.
• To optimize the conditions for quantitative lead (II) recovery.
• To evaluate the application of these reagents for lead (II) determination using diffusion reflectance spectroscopy.

Main Methods:

• Synthesis of xylenol orange and Fe(III)-xylenol orange complexes immobilized on silica.
• Sorption studies to determine optimal conditions (pH, sorbent amount, volume, time).
• Investigation of interfering ions tolerance.
• Lead (II) pre-concentration and detection via diffusion reflectance spectroscopy.

Main Results:

• Successfully synthesized and characterized immobilized xylenol orange-based solid-phase reagents.
• Optimized conditions for quantitative lead (II) recovery, including pH range (4.5-5.5).
• Achieved a detection limit of 2 µg/L for lead (II) with good tolerance to other metal ions.
• Demonstrated the method's applicability for lead (II) determination in real samples like natural water and foodstuffs.

Conclusions:

• Immobilized xylenol orange on silica is an effective sorbent for lead (II) pre-concentration.
• The developed method offers a sensitive and reliable approach for lead (II) analysis.
• This technique holds promise for environmental monitoring and food safety analysis.