Determination of Azide Ions in Blood by Pentafluorobenzyl Derivation Followed by GC-MS / 法医学杂志

Objective To establish a method for determination of the azide ions in blood by gas chromatography-mass spectrometry （GC-MS） following pentafluorobenzyl derivatization. Methods A blood sample of 0.2 mL was placed into a 10 mL glass test tube, and the internal standard sodium cyanide, derivatization reagent pentafluorobenzyl bromide and catalyst tetradecyl benzyl dimethyl ammonium chloride were added in turn. After vortex mixing, the mixture was heated with low-power microwave for 3 min. After centrifugation, the organic phase was taken for GC-MS analysis. Results The azide ions in blood had a good linear relationship in the mass concentration range of 0.5 to 20 μg/mL. The lowest detection limit was 0.25 μg/mL and the relative recovery was 91.36%-94.58%. The method was successfully applied to a case of death from sodium azide poisoning. The mass concentration of azide ions in the blood of the dead was 11.11 μg/mL. Conclusion The method developed in this paper has strong specificity and is easy to operate, which is suitable for the rapid detection of azide ions in blood.

A Novel Fluorescent Probe Based on Schiff Base for Dual Sensing of Zn2+and CN- / 分析化学

A novel Schiff base probe 4'-hydroxy-3'-((2-pyridin-2-ylmethylimino) methyl)-4-biphenyl carbonitrile (HPBC) for dual sensing of Zn2+and CN-was synthesized and characterized by various techniques such as UV-Vis, fluorescence, HRMS and NMR spectroscopy. HPBC was highly selective toward these two ions with different fluorescence signals in two different media. In EtOH-H2O(2:3,V/V;HEPES,pH 7.4),HPBC selectively bound Zn2+to form a 1:1 ligand/metal complex. Addition of Zn2+to the solution of HPBC resulted in a blue shift (△λ=15 nm) with a pronounced fluorescence enhancement at 468 nm, while there was no enhancement in the presence of other metal ions,especially Cd2+. HPBC displayed an"ON-OFF-ON"mode fluorescence change with alternative addition of Zn2+and EDTA. Hence, HPBC is a reversible and reusable sensor for Zn2+. The dynamic range of the assay is linear up to 4.0 μmol/L Zn2+ion and the limit of detection was 36.5 nmol/L,which was thousand fold lower than the WHO guideline (about 76 μmol/L) for drinking water. The fluorescence response of HPBC toward Zn2+was pH-dependent, and the maximal signal was observed at near neutral pH values, which makes it suitable for application in physiological conditions. Cell imaging studies demonstrate that this sensor is capable of sensing Zn2+in living cells. In DMSO-H2O (3:7,V/V) medium,addition of cyanide ion to HPBC led to deprotonation of the phenol hydrogen,resulting in a color change from colorless to pale yellow and a significant fluorescence enhancement at 510 nm. The probe exhibited high selectivity and sensitivity for CN- ion and the detection limit was 5.75×10-7mol/L. Finally,the use of a test strip of probe HPBC to detect cyanide was reported.