电子与计算机技术(仪器分析-英文版).ppt

Goals of Analytical Chemistry What is it? Identification Qualitative Analysis How much? Quantitative Analysis Analytical Instruments Data Domain – information encoded Non-electrical Domains (scale, number, chemical) Electrical Domains – (volts, current, charge) Analog Domains – continuous quantities (volts, current) Time Domains– (pulses, slopes) Digital Domains – (Off/On or Hi/Lo) Time Domains Time = Digital Domains Digital Domains Instrumental Components Instrument Components Fluorometer Components Selecting an Analytical Method Required Accuracy Amount of sample Concentration range(s) of analyte(s) Possible interferences Chemical and physical properties of matrix Number of samples Desirable Characteristics for an Analytical Method Speed Ease and Convenience Skill required of operator Cost and availability of equipment Per-samples cost Numerical Criteria forSelecting an Analytical Method Precision Absolute standard deviation Relative standard deviation Coefficient of variation Variance Bias Absolute systematic error Relative systematic error Sensitivity Calibration Analytical Detection Limit Blank plus three times Std. Dev. of blank Concentration Range Limit of Quantitation (LOQ) Limit of Linearity (LOL) Selectivity Effects of interferences Coefficient of Selectivity Precision –Figures of Merit Calibration Sensitivity Calibration Sensitivity (m) Analytical Sensitivity Signal Detection Limit Concentration Detection Limit Limits of Quantitation and Linearity Example-Sensitivity Selectivity Calibration Selectivity Instrumental Analysis Chapter 2 AC Circuits and Semiconductors Alternating Currents I Alternating Currents II Alternating Signals Alternating Signals with different amplitudes and phases I Alternating Signals with different amplitudes and phases II Alternating and Direct Currents –Root Mean Square Values Capacitors RC Circuits I RC Circuits II RC Circuits III RC Circuits IV RC Circuits V RC Circuits VI RC Circuits with ac Source I RC Circuits