Simultaneous quantitation of hydrazine and acetylhydrazine in human plasma by high performance liquid chromatography-tandem mass spectrometry after derivatization with p-tolualdehyde

•A HPLC-MS/MS method was developed to detect hydrazine and acetylhydrazine in human plasma.•A new derivatization reagent p-tolualdehyde was applied.•Sample pretreatments were simple without additional heating and purification.

A high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed for simultaneous quantitative analysis of hydrazine and acetylhydrazine in human plasma based on the strategy of p-tolualdehyde derivatization. The derivatization reactions were easily realized by ultrasonic manipulation for 40 min. Good separation of the derivatization products was achieved using a C18 column by gradient elution. The optimized mass transition ion-pairs (m/z) monitored for the two hydrazine derivatives were m/z 237.1 ≫> 119.9 and m/z 176.9 ≫> 117.8, respectively. The limit of detection (LOD) and limit of quantification (LOQ) for hydrazine were 0.002 and 0.005 ng mL−1 separately. And they were 0.03 and 0.05 ng mL−1 for acetylhydrazine, respectively. The linear range was 0.005-50 ng mL−1 for hydrazine and 0.05-500 ng mL−1 for acetylhydrazine with R2 greater than 0.999. The recovery range was determined to be 95.38-108.12% with the relative standard deviation (RSD) in the range of 1.24-14.89%. The method was successfully applied to detect 30 clinical plasma samples of pulmonary tuberculosis patients treated with isoniazid. The concentrations were from 0.04-1.99 ng mL−1 for hydrazine and 0.06-142.43 ng mL−1 for acetylhydrazine. The results indicated that our developed method had the potential for the detection of hydrazine toxicology in complex biological samples. Furthermore, the method has an important significance to clinical treatment with drugs.