一种可同时检测挥发性氯代烷烃和氯代烯烃的电子鼻的研制

开发了一种可用于快速检测挥发性氯代烷烃和氯代烯烃气体的电子鼻系统.该电子鼻系统的核心检测部件为3个金属氧化锡传感器及一个光离子化传感器(PID)所构成的传感器阵列.基于对9类单一成分标准气体和5类混合标准气体的测试分析建立了气体类型识别模型,然后通过加标实验与气相色谱法比较验证了电子鼻系统检测的有效性.结果表明:①电子鼻中各传感器对氯代烯烃和氯代烷烃的响应有差异.PID对氯代烷烃无响应,对氯代烯烃有线性响应(R2>0.997).传感器TGS2602对四氯化碳(CT)、三氯甲烷(TCM)和1,2-二氯乙烷(1,2-DCA)较为灵敏,对前两者的定量性较好,但对1,2-DCA的线性响应很差.传感器TGS2600和TGS2620对二氯甲烷(DCM)和1,2-DCA较为灵敏,且线性响应程度好(R2>0.995).②建立了基于传感器阵列信号的气体类型简单识别模型:选用PID计算氯代烯烃浓度,TGS2602计算CT和TCM浓度,TGS2600或TGS2620计算DCM和1,2-DCA浓度.③TGS2602对标准混合气体的响应强度小于单物质响应强度之和,其它传感器对标准混合气体的响应强度接近于单物质响应强度之和.④电子鼻对污染水样中DCM和四氯乙烯(PCE)混合气体的检测结果与气相色谱分析值呈线性相关,相关系数R2>0.96.

Implementation of an Electronic Nose for Rapid Detection of Volatile Chloralkane and Chloroalkene

An electronic nose, core detector of which was composed of three metal-doped SnO₂ gas sensors and a photo ionization detector (PID) as a sensor array, was developed for rapid detection of volatile chloralkane and chloroalkene. A gas recognition model was developed based on test and analysis with nine of pure gas and five of mixtures, and then the electronic nose was applied to several water samples and the validity was evaluated with a gas chromatography. The results revealed that the sensor array responded differently between the chloralkane and chloroalkene. PID was less sensitive to chloralkane, while linearly responded to chloroalkene (R²>0.997). Sensor TGS2602 performed sensitive to carbon tetrachloride (CT), trichloromethane (TCM) and 1,2-dichloroethane (1,2-DCA), with a linear response to the former two but a poor linear response to 1,2-DCA. Sensors TGS2600 and TGS2620 were by far more sensitive and linearly (R²>0.995) responded to dichloromethane (DCM) and 1,2-DCA. Therefore in the final gas recognition model, PID was used to determine the concentration of chloroalkene, sensor TGS2602 was used to determine CT and TCM, sensor TGS2600 or TGS2620 was used to determine DCM and 1,2-DCA. When applied to gas mixtures, sensor TGS2602 responded less sensitive than the sum of the response to each single component, while other sensors responded equally. The electronic nose showed a determined result linearly correlated to GC (R²>0.96) as applied to samples with a mixture of DCM and perchloroethylene.