Objective:To report an iodine analysis instrument with sequential injection of atomic fluorescence mercury analyzer and a miniature constant-temperature digestion apparatus to be used for batch sample pretreatment,and set up a method of its analysis system.Methods: Connect the program-controlled injector pump,the program-controlled multi-channel sequence injection valve and two tandem mercury vapor double bubble bottles which have ten times volume differ,and complete mercury vapor occurrence,concentration and the second quick explode gas with the microcomputer control.Use a precise control of stepping motor driver 12 channel selection valve connect the light pool with sample solution,reductant,and mercury absorbing liquid.Results: The linear range is 0.0006861 μg/L～10 μg/L,the linear error is 0.0006861 μg/L～10 μg/L,and the detection limit is 0.000681 μg/L.The standard deviation of carp is 4.01800 and the recovery rate is 97.8%.The standard deviation of milk powder is 0.18688 and the recovery rate is 96.5%.Conclusion: Realize automation,and improve speed,sensitiity and accuracy analysis.
The total steroidal saponins, particularly its major steroidal sapogenin (diosgenin), are the main active principles of fenugreek seed extract. In this study, an ethanol-salt aqueous two-phase system (ATPS) was explored for the purification of the total steroidal saponins, and the process conditions were optimized by response surface methodology (RSM). Under the optimized conditions, the RSM predicted recovery of the total steroidal saponins in the top phase of ATPS was 97.9%, which agreed with the average experimental recovery (98.3 ± 4.2% ( n = 6)). Moreover, a rapid micellar electrokinetic chromatography (MEKC) method was developed for the determination of diosgenin from extracts. The diosgenin content in the ATPS top phase extract was 3-fold higher than that in crude extract, suggesting this ATPS having a great potential for purification pharmacological active ingredients from fenugreek seeds.
A new kind of coordinated ionic liquid,[(CH3CH2)4N+Cl-·3C6H11NO],was synthesized from caprolactam and tetraethyl ammonium chloride and the system phase diagram of(CH3CH2)4N+Cl-/C6H11NO was obtained through the measurement of temperature of liquid line.Its structure was characterized by IR and XRD,and the TGA-DTA pattern and phase diagram of the coordinated ionic liquid showed that the range of thermal stability was from room temperature to about 250℃,which meant it was more stable than the common organic solvents.
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In this research, a near infrared multi-wavelength noninvasive blood glucose monitoring system with distributed laser multi-sensors is applied to monitor human blood glucose concentration. In order to improve the monitoring accuracy, a multi-sensors information fusion model based on Back Propagation Artificial Neural Network is proposed. The Root- Mean-Square Error of Prediction for noninvasive blood glucose measurement is 0.088mmol/L, and the correlation coefficient is 0.94. The noninvasive blood glucose monitoring system based on distributed multi-sensors information fusion of multi-wavelength NIR is proved to be of great efficient. And the new proposed idea of measurement based on distri- buted multi-sensors, shows better prediction accuracy.
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