基于均匀和正交试验设计的胶束电动毛细管色谱法同时测定消毒剂和抗抑菌产品中3种核苷类抗病毒药物

为防止消毒剂与抗抑菌产品中违规添加核苷类抗病毒药物,建立了胶束电动毛细管色谱（MEKC）同时分离测定消毒剂与抗抑菌产品中3种核苷类抗病毒药物（更昔洛韦、阿昔洛韦和喷昔洛韦）的新方法。通过3因素7水平均匀试验设计和4因素4水平的正交试验设计优化了十二烷基硫酸钠（SDS）、磷酸二氢钠（NaH₂PO₄）及硼砂（Na₂B₄O₇）在分离缓冲液中的浓度,最大限度地实现了3种核苷类抗病毒药物在短时间内的有效分离。以30.2 cm×50 μ m（有效长度为20 cm）未涂层熔融石英毛细管为分离柱,以25 mmol/L NaH₂PO₄+10 mmol/L Na₂B₄O₇（pH 7.41）+140 mmol/L（SDS）为分离缓冲溶液,分离电压为10 kV;进样压力为0.003 Pa,进样时间为4 s;检测波长为250 nm。3种抗病毒药物在一定的浓度范围内线性关系良好,相关系数r均不小于0.9995。3种抗病毒药物的检出限均为2.0 mg/kg,定量限均为7.0 mg/kg。低、中、高浓度加标回收率为85.4%~104.1%,相对标准偏差（RSD）均小于8.0%。该方法简便,快速,适于检测消毒剂与抗抑菌产品中更昔洛韦、阿昔洛韦和喷昔洛韦。     

Detection performance improvement of photon counting chirped amplitude modulation lidar with response probability correction

Geiger mode avalanche photodiode detector(Gm-APD) possesses the ultra-high sensitivity. Photon counting chirped amplitude modulation(PCCAM) light detection and ranging(lidar) uses the counting results of the returned signal detected by Gm-APD to mix with the reference signal, which makes PCCAM lidar capable of realizing the ultra-high sensitivity, and this is very important for detecting the remote and weak signal. However, Gm-APD is a nonlinear device, different from traditional linear detectors. Due to the nonlinear response of Gm-APD, the counting results of the returned signal detected by Gm-APD are different from those of both the original modulation signal and the reference signal. This will affect the mixing effect and thus degrade the detection performance of PCCAM lidar. In this paper, we propose a response probability correction method. First, the response probability correction model is established on the basis of Gm-APD Poisson probability response model. Then, the response probability correction model is used to adjust the original modulation signal that is used to drive laser, in order to make the counting results of the returned signal detected by Gm-APD better mix with the local reference signal in the same form. Through this method, the detection performance of PCCAM lidar is enhanced efficiently.