A microassay for urinary phenol using capillary gas chromatography and optimised enzymic hydrolysis

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Toxicology

Background:

• Benzene exposure assessment relies on monitoring urinary phenol levels.
• Existing methods for urinary phenol assay may lack efficiency or sensitivity.
• Accurate measurement of phenol conjugates is essential for reliable benzene exposure evaluation.

Purpose of the Study:

• To develop and validate an improved capillary gas chromatography (GC) method for the quantitative assay of urinary phenol.
• To enhance the accuracy and efficiency of phenol measurement for benzene exposure assessment.
• To establish a sensitive microassay for monitoring low concentrations of urinary phenol.

Main Methods:

• Utilized enzymatic hydrolysis with Helix pomatia extract for complete liberation of phenol from glucuronide and sulphate conjugates.
• Incorporated 2,4-xylenol as an internal standard for rapid, single-step extraction of phenol.
• Employed capillary gas chromatography for precise separation and quantification of urinary phenol.

Main Results:

• The method achieved complete hydrolysis of phenol conjugates, yielding clean chromatograms.
• The assay demonstrated high sensitivity, capable of measuring phenol concentrations as low as 1 mg/l in urine.
• The incorporation of an internal standard facilitated a rapid and efficient single-step extraction process.

Conclusions:

• The improved capillary GC method provides a sensitive and reliable means for assessing benzene exposure through urinary phenol analysis.
• This microassay is suitable for routine monitoring of occupational and environmental benzene exposure.
• The method's efficiency and sensitivity offer advantages over existing techniques for toxicological studies.