Laboratory Robotics and Automation最新文献

An automated monitoring system for quality of treated wastewater from a power plant by incorporating flow injection analysis (FIA) has been developed. Measurements for pH, conductivity, dissolved oxygen, and water level are made by using sensors/probes. The FIA procedures are for sulfate, phosphate, and iron. The online monitoring system accommodated in a hut, at the sampling site, 10 km from the control station, is automatically operated by making use of process logic control. The central control station links to the monitoring instruments via a mobile radio set for control of the instrument operation and data acquisition and evaluation. © 2000 John Wiley & Sons, Inc. Lab Robotics and Automation 12:164–170, 2000

This article reviews the use of a wall-jet type flow-through detector for the potentiometric determination of quinine and paraquat ions, respectively, undertaken within our research laboratories. The detector allows the evaluation of the analytical response characteristics of the poly(vinyl chloride)-based membranes to be done in the flow injection analysis mode. Such ion-selective electrode membranes, containing either ion-exchangers or neutral carrier type of electroactive component, in conjunction with appropriate plasticizing solvent, and sometimes other membrane additive as was the case for paraquat selective membranes, can be conveniently applied to the detector assembly. Utilization of the flow-through detector allows studies on the sensing of the antimalarial drug, quinine, and the herbicide, paraquat, to be conducted conveniently. Details of the flow-through detector and its performance when used for the determination of the respective ion of interest under different matrices are described. © 2000 John Wiley & Sons, Inc. Lab Robotics and Automation 12:133–137, 2000

We propose cost-effective flow injection analysis systems for acetic acid. The flow systems can be assembled with different types of components, including a clinical saline bag and laboratory-made detectors, resulting in various degrees of automation, varying from very simple ones to fully computerized control. The flow injection titrations are based on neutralization and are monitored by either spectrophotometry or conductometry. The flow injection procedures can be performed under conditions at non-steady or steady states. The proposed procedures are demonstrated for the application of analysis of vinegar samples for acidity. © 2000 John Wiley & Sons, Inc. Lab Robotics and Automation 12:129–132, 2000

A rapid, sensitive flow injection (FI) method with chemiluminescence (CL) detection for the determination of trace amounts of hydrogen peroxide in natural water is described. This method is based on the reaction of luminol with hydrogen peroxide catalysed by cobalt(II) in an alkaline medium. Sodium dodecyl sulphate (SDS) was used as sensitizer agent, and its presence greatly accelerated the reaction and enhanced the CL intensity. An FI stopped-flow technique was introduced to the CL reaction to increase sensitivity. Optimal conditions for the chemiluminescence reaction were examined. The sampling frequency was 50 hr⁻¹ for injection volumes of 100 µL. The detection limit of hydrogen peroxide, defined as 3 times the standard deviation of the blank, was 0.5 nM in high purity water, and the working linear range was 1 to 105 nM. For the determination of 15 nM and 52 nM hydrogen peroxide, the relative standard deviations were 2.8 and 2.3% respectively (n = 11). The method has been applied to the determination of hydrogen peroxide in natural water samples. © 2000 John Wiley & Sons, Inc. Lab Robotics and Automation 12:149–156, 2000

A modified version of the flow injection method for the determination of dissolved organic carbon (DOC) developed by Koshy et al. is described. This method is capable of DOC measurements in the presence of high levels of chloride and has a method detection limit of 0.8 mg C/L, a linear response range of 0–35 mg/L, carbon recovery of 98 ± 9%, and a sample throughput of 60 h⁻¹. © 2000 John Wiley & Sons, Inc. Lab Robotics and Automation 12:157–163, 2000

Development of industrial areas must be followed by increased monitoring of industrial wastewater systems. One method for continuous monitoring of water quality is flow injection analysis (FIA). An FIA method does not need to mix the reagents and sample manually as in methods based on conventional spectrophotometry and colorimetry; they are delivered by peristaltic pump to the manifold, and after mixing, they go into the flow cell. The parameters that can be determined by FIA are nitrite, nitrate, ammonia, phosphate, silica, arsenic, and mercury. © 2000 John Wiley & Sons, Inc. Lab Robotics and Automation 12:142–148, 2000

This work describes the use of an audio card for interfacing a spectrophotometer with a personal computer (PC). Digital recording on the computer was carried out using a voltage-controlled oscillator (VCO) and an audio card primarily installed in a multimedia PC. The output voltage of the spectrophotometer was transformed to frequency by the VCO. The audio card, linked to the VCO, converts the VCO output to digital data. An executable program named SigREC was written in C language using Microsoft Visual C++ 5.0 compiler to record the data.

The interfacing system was tested and compared with a chart recorder to record signals from a flow injection system with a spectrophotometer as a detector. The audio card system gave a better recording precision (RSD = 1.8%) when compared to the chart recorder (RSD = 2.5%). © 2000 John Wiley & Sons, Inc. Lab Robotics and Automation 12:138–141, 2000

A robust automatic flow analyzer for laboratory routine analysis or industrial process analysis is introduced, which is based on syringe piston pumps, a rotary valve, a light emitting diode (LED) and phototransistor photometer, and a single chip microcomputer system. Both the pumps and the valve are driven by stepper motors with photoswitch position detection. By movement coordination of the pumps and the valve, no separate waiting time is necessary for the syringe to be refilled or discharged, and the leakage problem of the valve is also alleviated. The analyzer can be operated in two modes, flow-injection-analysis mode, into which most current FIA methods developed with peristaltic pumps can be easily adapted, and microtitration mode, with which major components in a sample can be titrated quickly, accurately, and in a microchemical way. To demonstrate, the analyzer was employed both for the determination of trace amounts of tungsten in the raffinate of ammonium paratungstate (APT) processing with FIA mode and for the determination of caustic hydroxide in the industrial production of aluminum oxide with microtitration mode. The typical sampling rates are 60 and 45 samples h⁻¹ for FIA mode and titration mode, respectively. © 2000 John Wiley & Sons, Inc. Lab Robotics and Automation 12:108–113, 2000

An on-line microwave oven was employed in this study to accelerate the coordination reactions between Rh(III), Pd(II), and 2-(3,5-dicloro-2-pyridyl-azo)-5-dimethylaminoaniline (3,5-diCl-PADMA) in HOAc-NaOAc media. Two sensitive flow-injection spectrophotometric methods have been established for the determination of Rh and sequential determination of Rh and Pd, respectively.

Two important parameters in on-line Microwave-FIA, T₁ and T₂, were investigated. The difference in the effect of the microwave irradiation on the reactions was explained. The proposed methods are applied to the determination of Rh in the waste and sequential determination of Pd and Rh in artificial samples with satisfactory results. © 2000 John Wiley & Sons, Inc. Lab Robotics and Automation 12:91–96, 2000