Sample preparation method with ultrafiltration for whole blood thiosulfate measurement

Area of Science:

• Analytical Chemistry
• Biochemistry
• Toxicology

Background:

• Quantitative analysis of thiosulfate is crucial for diagnosing hydrogen sulfide poisoning.
• Traditional methods using liquid chromatography-tandem mass spectrometry (LC-MS/MS) require large amounts of blood for calibration standards due to matrix effects.
• This limitation hinders rapid and sensitive thiosulfate measurements.

Purpose of the Study:

• To develop an improved method for thiosulfate quantification that overcomes the limitations of traditional calibration procedures.
• To investigate the stability of thiosulfate in refrigerated blood samples using the novel method.

Main Methods:

• Incorporation of an ultrafiltration step (50-kDa exclusion membrane) in sample preparation.
• Generation of calibration curves using standard solutions prepared with pure water instead of blood.
• Measurement of thiosulfate concentration in refrigerated blood samples (stored at 4°C) over 96 hours.

Main Results:

• The ultrafiltration method enabled thiosulfate quantification using a pure water-based calibration curve, eliminating the need for blood standards.
• Thiosulfate concentration in whole blood showed a reduction of less than 10% during 2 days of refrigeration.
• The developed method successfully resolved the issue of requiring large blood volumes for standard preparation.

Conclusions:

• The ultrafiltration technique significantly simplifies thiosulfate analysis for hydrogen sulfide poisoning diagnosis.
• The method is robust, allowing for reliable thiosulfate measurements even after several days of sample refrigeration.
• This advancement enhances the practicality and efficiency of thiosulfate diagnostics.