Determination of procaine in equine plasma and urine by high-performance liquid chromatography.

The article discusses a more reliable and sensitive method developed for measuring procaine levels in horse plasma and urine using high-performance liquid chromatography. Previously, varying results were obtained from different labs using older techniques, which spurred the formation of this new approach.

Research Background and Objectives

• The researchers were motivated by consistent differences in measurement of procaine levels in equine plasma and urine from three independent laboratories using current measurement methods.
• The main objective of this study was to develop a sensitive, authentic, and reproducible method to measure procaine in equine plasma and urine using high-performance liquid chromatography (HPLC).

Methodology

• Standardbred mares were administered either a penicillin G procaine preparation intramuscularly or procaine hydrochloride subcutaneously.
• Blood and urine samples were collected at defined time intervals for analysis.

Results and Discussion

• The method proved to be very sensitive. By HPLC, the detection limits for procaine in plasma and urine were found to be very low: 1 and 10 ng/mL, respectively.
• In contrast, when using the GC-NPD method, procaine in plasma could not be detected, whilst the urinary detection limit was 50 ng/mL.
• It was observed that the concentration of fluoride in the collection tubes and repetitive freeze-thawing influenced plasma procaine measurement.
• The level of urinary pH was identified as a factor in estimation of urine procaine levels.
• Recovery and reproducibility of results were greater at a lower pH (5) compared to a higher one (7).

Conclusions

• The HPLC method developed in this study provides a simple, sensitive, and reliable way of quantifying procaine levels in equine plasma and urine.
• The findings bring us closer to uniformity and reliability in procaine measurement techniques in equine studies.