A new and simple analytical method for the detection of cyanide has been developed using a dimethoxytiazinyl (DMT) derivatization technique. The DMT derivatives of cyanide (DMT-CN) produced in the reactions of cyanide with 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium (DMT-MM) known as a harmless condensing reagent were detected by gas chromatography-mass spectrometry with a slightly-polar capillary column, and were identified using an authentic DMT-CN standard synthesized in our laboratory. The conditions affecting the derivatization reaction were optimized (pH 9; temperature, 25 ℃; reaction time, 20 min) by investigating the yield of the DMT-CN. The optimized method exhibited a high degree of linearity (r2=0.9980-0.9999) for cyanide in distilled water and three beverages (tea, coffee and milk) without major interference of matrix compounds, over the concentration range from 6.0 to 600 μg/mL. The limits of detection were estimated to be 0.2 μg/mL for distilled water and 0.3 μg/mL for the beverages. The obtained values for accuracy and precision were less than 10% for two concentration levels (30 and 300 μg/mL) in the beverages. These results guarantee the satisfactory sensitivity, reproducibility and reliability of the present method. The method could be also applicable for the detections of cyanide, azide and sulfide in blood samples. This report demonstrates high-throughput, high-sensitive, applicable, cheap and safe properties of the DMT-derivative method for cyanide determination.
