Quantitative analysis of lignocaine and metabolites in equine urine and plasma by liquid chromatography-tandem mass spectrometry.

The research paper describes a way to accurately analyze a drug called lignocaine, and its main metabolites in horse urine and plasma samples using a technique known as liquid chromatography-tandem mass spectrometry.

Technique Used

• The researchers used a method known as liquid chromatography-tandem mass spectrometry. This is a commonly used molecular biology technique which combines the physical separation capabilities of liquid chromatography with the analysis capabilities of mass spectrometry. This method allows for detection and identification of chemicals within a sample.

Sample Preparation

• The samples used in this study were equine urine and plasma. They were prepared using a process called solid-phase extraction, which is a technique used to separate certain compounds from a solution based on their physical and chemical properties.
• The internal standard used in the testing was lignocaine-d(10). An internal standard is a compound that is added in a fixed amount to a sample and used as a reference point in the analysis.

Analysis

• In the analysis, the scientists used an octadecylsilica reversed-phase column and a gradient mobile phase of acetonitrile and 0.1% (v/v) aqueous formic acid to separate the components of the sample.
• The target components and the internal standard were identified using certain identifiable characteristics known as transitions.

Validation and Use of the Method

• The effectiveness and reliability of this method were validated through checking for instrument linearity, repeatability, detection limit (IDL), method linearity, repeatability, detection limit (MDL), quantitation limit (LOQ) and recovery.
• After confirming its validity, the method was used to analyze both plasma and urine samples from a thoroughbred horse that had been given lignocaine subcutaneously. This demonstrated the practical application of the method in a real-world scenario.