压电石英传感器测定空气中氮氧化物

通过电化学活化和硅烷偶联剂在石英谐振器的金电极表面修饰对氮氧化物(NO_x)敏感的金属酞菁化合物,制成压电气体传感器.探讨了不同敏感材料对NO_x的响应灵敏度、检出限及载气流速、温度和干扰气体等对传感器的响应和回复特性的影响.结果表明:酞菁铅最敏感;其适宜的载气流速为40 mL/min,温度范围为10~40 ℃;在9.55×10_-4~1.91 mg/m₃质量浓度范围内,有良好的线性响应关系;用于大气中NO_x的测定,有较好的可靠性和准确性.使用寿命约300次. 

Determination of Nitrogen Oxide in the Atmosphere Using Piezoelectric Quartz Sensor

The piezoelectric quartz sensor(PQS) was prepared by coating metal phthalocyanines(PcM) sensitive to nitrogen oxide(NO_x) on the surface of Au electrode of quartz crystal resonator by electrochemical activation and silane coupling agent.The response sensitivities and detection limits of a variety of materials to NO_x,and effects of the flow velocity of carrier gas,temperature and recovery characteristics of sensors were investigated.The results indicated that lead phthalocyanine was the most sensitive to NO_x,that the appropriate flow velocity of carrier gas was 40 mL/min and temperature range was 10~40 ℃,that the responses of sensor are fairly linear when the mass concentration is from 9 55×10_-4 to 1 91 mg/m₃,and that it has a good reliability and accuracy in the determination of NO_x in the atmosphere.It could be used about 300 times.