L1: INTRO TO ANALYTICAL CHEM

• Analytical chemistry is a measurement science consisting of a set of powerful ideas and methods that are useful in all fields of science and medicine.
• Qualitative analysis reveals the identity of the

  elements and compounds in a sample.
• Quantitative analysis indicates the amount of

  each substance in a sample
• GRAVIMETRIC METHODS Determine the mass of the analyte or some compound chemically related to it.
• VOLUMETRIC METHOD Determines the volume of a solution containing sufficient reagent to react completely with the analyte.
• ELECTROANALYTICAL METHODS Involve the measurement of such electrical properties as voltage, current, resistance, and quantity of electrical charge.
• SPECTROSCOPIC METHODS are based on measurement of the interaction between electromagnetic radiation and analyte atoms or molecules or on the production of such radiation by analytes.
• Sampling involves obtaining a small mass of a material whose composition accurately represents the bulk of the material being sampled.
• Sampling is frequently the most difficult step in an analysis and the source of greatest error. The final results of an analysis will never be any more reliable than the reliability of the sampling step.
• An interference is a species that causes an error in an analysis by enhancing or attenuating (making smaller) the quantity being measured
• Species other than the analyte that affect the final measurement are called interferences or interferents.
• CALIBRATION AND MEASUREMENT Ideally, the measurement of the property is directly proportional to the concentration..
• CALCULATING RESULTS Computing analyte concentrations are based on the raw experimental data collected in the measurement step, the characteristics of the measurement instruments, and the stoichiometry of the analytical reaction.
• EVALUATING RESULTS BY ESTIMATING THEIR RELIABILITY analytical results are incomplete without an estimate of their reliability.