Determination of cyanogen chloride in organic and water matrices by gas chromatography-mass spectrometry based on thiol derivatization

Cyanogen chloride (C1CN) has been widely used in industrial production. C1CN is also listed in the Schedule of the Chemical Weapons Convention (CWC). The use of traditional colorimetric analysis or gas chromatography for the detection of C1CN has been characterized by low efficiency and poor sensitivity. In this study, a method was established for the qualitative analysis and quantitative detection of C1CN in organic and water matrices by gas chromatography-mass spectrometry (GC-MS) based on thiol derivatization. 1-Butylthiol was selected as the optimal derivatization reagent. The optimal temperature for thiol derivatization in the organic matrices was 40 degrees C and the reaction time was 10 min. The pH for derivatization was approximately 9. The C1CN in the organic matrices was directly analyzed by GC-MS after derivatization. The conditions of C1CN derivatization in the water matrices were the same as those in the organic matrices. After the derivatization of C1CN, headspace-solid phase microextraction (HS-SPME) was employed during sample preparation for water matrices. Different temperatures for HS-SPME were explored, and the optimal temperature was found to be 55 degrees C. The product of thiol derivatization was confirmed as butyl thiocyanate. The main fragmentation patterns and mass spectrometric cleavage pathway were investigated by GC-MS/MS. The quantitative determination of C1CN in organic and water matrices was conducted via the internal standard and external standard methods, respectively. C1CN showed good linearity in the corresponding ranges in the organic and water matrices. The correlation coefficients for both matrices were greater than 0. 99. The linearities of C1CN in the organic and water matrices were in the range of 20-2 000 mu g/L and 20-1 200 mu g/L, respectively. An organic sample and water samples from different substrates were selected to verify the accuracy and precision of the method at three spiked levels. The average spiked recoveries of C1CN in the organic sample and water samples were 87. 3%-98. 8% and 97. 6%-102.2%, respectively. The corresponding relative standard deviations (RSDs, n = 6) were 2. 1%-4. 7% and 2. 8%-4. 2%. The derivatization method established in this study showed good reaction specificity. The method was successfully applied in the analysis of samples obtained from the Organisation for the Prohibition of Chemical Weapons (OPCW). The method established in this study for the detection of C1CN showed high sensitivity and precision, and could aid in the analysis and detection of C1CN in the environment.