A simpler potentiometric method for histamine assessment in blood sera

Area of Science:

• Analytical Chemistry
• Biochemistry
• Materials Science

Background:

• Histamine intolerance arises from impaired histamine degradation, often due to reduced diamine oxidase (DAO) activity.
• Histamine excess can mimic allergic reactions, necessitating reliable methods for its detection in biological and food samples.
• Accurate histamine quantification is crucial for identifying risk factors associated with histamine intolerance.

Purpose of the Study:

• To develop a novel histamine-selective electrode for analyzing biological samples.
• To utilize cucurbit[6]uril (CB[6]) as a selective ionophore in the electrode's polymeric membrane.
• To miniaturize the electrode for integration into a flow system for high-throughput analysis.

Main Methods:

• A histamine-selective electrode was fabricated using cucurbit[6]uril (CB[6]) as the ionophore in a PVC membrane, incorporating multi-walled carbon nanotubes.
• The electrode's performance was optimized for pH range, response time, Nernstian slope, and detection limits.
• A sequential-injection lab-on-valve flow system was developed, integrating the miniaturized electrode for automated sample analysis.
• Solid-phase extraction using Oasis MCX cartridges was employed for efficient pretreatment of blood serum samples.

Main Results:

• The developed electrode exhibited a rapid response time of approximately 13 seconds and a Nernstian slope of 30.9 mV/decade.
• The electrode achieved a low detection limit of (3.00 ± 0.61) × 10^-7 mol/L.
• The lab-on-valve system allowed for the analysis of up to 30 samples per hour.
• High recovery rates (97-118%) were obtained for histamine determination in spiked blood serum samples, demonstrating method suitability for biological matrices.

Conclusions:

• The novel histamine-selective electrode based on CB[6] is effective for histamine determination in biological samples.
• The integrated flow system offers a rapid and efficient method for analyzing histamine levels.
• This technology holds promise for improved diagnosis and management of histamine intolerance.