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- https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Analytical_Chemistry_2.1_(Harvey)/07%3A_Obtaining_and_Preparing_Samples_for_Analysis/7.01%3A_The_Importance_of_SamplingThis page discusses the importance of sampling in achieving accurate and precise chemical analyses, specifically related to ACS Reagent Grade specifications. A key point is that accurate sampling is c...This page discusses the importance of sampling in achieving accurate and precise chemical analyses, specifically related to ACS Reagent Grade specifications. A key point is that accurate sampling is crucial to minimize errors and meet standards, such as limiting iron in NaBr to under 5 ppm. The text also explains variance in sampling and analytical methods, illustrating the propagation of uncertainty through examples and exercises.
- https://chem.libretexts.org/Courses/Los_Angeles_Trade_Technical_College/Analytical_Chemistry/2%3A_Analytical_Chemistry_2.0_(Harvey)/06%3A_Standardizing_Analytical_Methods/6.1%3A_Analytical_StandardsTo standardize an analytical method we use standards containing known amounts of analyte. The accuracy of a standardization, therefore, depends on the quality of the reagents and glassware used to pre...To standardize an analytical method we use standards containing known amounts of analyte. The accuracy of a standardization, therefore, depends on the quality of the reagents and glassware used to prepare these standards. We divide analytical standards into two categories: primary standards and secondary standards.
- https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Instrumental_Analysis_(LibreTexts)/05%3A_Signals_and_Noise_(TBD)When we try to calibrate an analytical method or to optimize an analytical system, our ability to do so successfully is limited by the uncertainty, or noise, in our measurements and by background sign...When we try to calibrate an analytical method or to optimize an analytical system, our ability to do so successfully is limited by the uncertainty, or noise, in our measurements and by background signals that interfere with our ability to measure the signal of interest to us. In this chapter we will consider how we characterize noise, example of sources of noise, and ways to clean up our data by decreasing the contribution of noise to our measurements and by correcting for the presence of backgr
- https://chem.libretexts.org/Courses/Los_Angeles_Trade_Technical_College/Analytical_Chemistry/2%3A_Analytical_Chemistry_2.0_(Harvey)/04%3A_The_Vocabulary_of_Analytical_Chemistry/4.4%3A_Selecting_an_Analytical_MethodA method is the application of a technique to a specific analyte in a specific matrix. We can develop an analytical method for determining the concentration of lead in drinking water using any of the ...A method is the application of a technique to a specific analyte in a specific matrix. We can develop an analytical method for determining the concentration of lead in drinking water using any of the techniques mentioned in the previous section. The requirements of the analysis determine the best method and consideration is given the following criteria: accuracy, precision, sensitivity, selectivity, robustness, ruggedness, scale of operation, analysis time, availability of equipment, and cost.
- https://chem.libretexts.org/Courses/Los_Angeles_Trade_Technical_College/Analytical_Chemistry/2%3A_Analytical_Chemistry_2.0_(Harvey)/07%3A_Equilibrium_Chemistry/7.06%3A_Ladder_DiagramsIn this section we introduce the ladder diagram as a simple graphical tool for evaluating the equilibrium chemistry. Using ladder diagrams we will be able to determine what reactions occur when combin...In this section we introduce the ladder diagram as a simple graphical tool for evaluating the equilibrium chemistry. Using ladder diagrams we will be able to determine what reactions occur when combining several reagents, estimate the approximate composition of a system at equilibrium, and evaluate how a change to solution conditions might affect an analytical method.
- https://chem.libretexts.org/Courses/Northern_Alberta_Institute_of_Technology/CHEM1130_Principles_in_Chemistry_I/4%3A_Chemical_Calculations/4.8%3A_UV/4.8%3A_UV%2F%2FVis_and_IR_SpectroscopyThe 1930s and 1940s saw the introduction of photoelectric transducers for ultraviolet and visible radiation, and thermocouples for infrared radiation. As a result, modern instrumentation for absorptio...The 1930s and 1940s saw the introduction of photoelectric transducers for ultraviolet and visible radiation, and thermocouples for infrared radiation. As a result, modern instrumentation for absorption spectroscopy became routinely available in the 1940s—progress has been rapid ever since. Frequently an analyst must select—from among several instruments of different design—the one instrument best suited for a particular analysis. In this section we examine several different instruments for mole
- https://chem.libretexts.org/Courses/Los_Angeles_Trade_Technical_College/Analytical_Chemistry/2%3A_Analytical_Chemistry_2.0_(Harvey)/15%3A_Developing_a_Standard_Method/15.3%3A_Validating_the_Method_as_a_Standard_MethodFor an analytical method to be useful, an analyst must be able to achieve results of acceptable accuracy and precision. Verifying a method, as described in the previous section, establishes this goal ...For an analytical method to be useful, an analyst must be able to achieve results of acceptable accuracy and precision. Verifying a method, as described in the previous section, establishes this goal for a single analyst. Another requirement for a useful analytical method is that an analyst should obtain the same result from day to day, and different labs should obtain the same result when analyzing the same sample. The process by which we approve method for general use is known as validation.
- https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Analytical_Chemistry_2.1_(Harvey)/10%3A_Spectroscopic_Methods/10.07%3A_Atomic_Emission_SpectroscopyThis page discusses atomic emission spectroscopy (AES), a method for analyzing elements by recording the light emitted from excited atoms. The historical development of AES is highlighted, with applic...This page discusses atomic emission spectroscopy (AES), a method for analyzing elements by recording the light emitted from excited atoms. The historical development of AES is highlighted, with applications evolving from flame and spark techniques to plasma sources. AES is suitable for multielemental analysis and involves equipment like atomic emission spectrometers using flames or plasmas.
- https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Analytical_Chemistry_2.1_(Harvey)/15%3A_Quality_Assurance/15.04%3A_Evaluating_Quality_Assurance_DataThe text discusses two approaches to developing a quality assurance program in analytical chemistry: the prescriptive approach and the performance-based approach. The prescriptive approach involves a ...The text discusses two approaches to developing a quality assurance program in analytical chemistry: the prescriptive approach and the performance-based approach. The prescriptive approach involves a strict protocol for quality assessment, often required by regulatory agencies, while the performance-based approach allows laboratories flexibility, using control charts to monitor statistical control. Control charts help detect errors, ensuring precision and accuracy in analysis.
- https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Instrumental_Analysis_(LibreTexts)/24%3A_Coulometry/24.02%3A_An_Introduction_to_Coulometric_Methods_of_AnalysisIn this section we consider the experimental parameters and instrumentation needed to develop a controlled-potential coulometric method of analysis and its applications.
- https://chem.libretexts.org/Courses/Los_Angeles_Trade_Technical_College/Analytical_Chemistry/2%3A_Analytical_Chemistry_2.0_(Harvey)/16%3A_Quality_Assurance/16.4%3A_Evaluating_Quality_Assurance_DataNow we turn our attention to how we incorporate this quality assessment data into a complete quality assurance program. There are two general approaches to developing a quality assurance program: a pr...Now we turn our attention to how we incorporate this quality assessment data into a complete quality assurance program. There are two general approaches to developing a quality assurance program: a prescriptive approach, in which we prescribe an exact method of quality assessment, and a performance-based approach in which we can use any form of quality assessment, provided that we can demonstrate an acceptable level of statistical control.
