Work

A two-dimensional liquid chromatography method with optimized pretreatment for detection of guanidine compounds in animal liver and kidney

Year: 2025

Type: article

Abstract: This study is centered on optimizing the derivatization reaction conditions and the protein precipitation reagent system for the detection of guanidine compounds (GCs) in animal liver and kidney. It introduces a two-dimensional liquid chromatography combined with ultraviolet detection (2D-LC-UV) method. The optimal derivatization conditions were identified through an orthogonal experiment, with the most favorable reaction conditions being 100 °C for 5 min, and optimal concentrations of benzoin and potassium hydroxide (KOH) determined to be 30 mmol/L and 8 mol/L, respectively. Furthermore, a 50 % methanol-0.5 % hydrochloric acid solution was selected as an effective protein precipitation reagent. Methodological validation demonstrated that, in mouse liver and kidney tissues, the linear range for GCs was 5–500 μmol/L (r 2 > 0.99), with a limit of quantification of 5 μmol/L. Analysis of animal samples revealed an organ-specific metabolic distribution of GCs. This study furnishes reliable technical support for the detection of guanidino compounds in animal biological samples. • Optimized derivatization: 100 ° C, 5 min, 30 mmol/L benzoin & 8 Mol/L KOH → complete reaction • Significance: Maximizes UV sensitivity for trace GC detection. • Novel protein precipitant: 50 % methanol-0.5 % HCl → high GC recovery. • Significance: Minimizes matrix interference while preserving targets. • Validated 2D-LC-UV method: Linear 5–500 μmol/L (LOQ = 5 μmol/L) in tissues. • Significance: Reliable quantification in complex biological matrices. • Organ-specific GC distribution: GSA dominant in liver; GAA lowest in kidney. • Significance: Reveals metabolic partitioning across species.

Source: Food Chemistry X

DOI: 10.1016/j.fochx.2025.103089