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- https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Analytical_Chemistry_2.1_(Harvey)/10%3A_Spectroscopic_Methods/10.09%3A_ProblemsThe document appears to be focused on various analytical chemistry problems involving spectrophotometry, colorimetry, and molecular absorption techniques in different contexts such as determining conc...The document appears to be focused on various analytical chemistry problems involving spectrophotometry, colorimetry, and molecular absorption techniques in different contexts such as determining concentrations of elements or compounds in different scenarios like solutions, beverages, and solid matrices. The problems cover applications of Beer???s Law, stoichiometry of complex formation, and effects of instrumental limitations.
- 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/15.1%3A_Optimizing_the_Experimental_ProcedureDeveloping a standard method requires optimizing multiple aspects. Using the terminology of statisticians, we call the solution’s absorbance the system’s response. Hydrogen peroxide and sulfuric acid ...Developing a standard method requires optimizing multiple aspects. Using the terminology of statisticians, we call the solution’s absorbance the system’s response. Hydrogen peroxide and sulfuric acid are factors whose concentrations, or factor levels, determine the system’s response. To optimize the method we need to find the best combination of factor levels. Usually we seek a maximum response, but sometimes, such as minimizing an analysis’s percent error, we are looking for a minimum response.
- https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Instrumental_Analysis_(LibreTexts)/13%3A_Introduction_to_Ultraviolet_Visible_Absorption_Spectrometry
- https://chem.libretexts.org/Courses/Lakehead_University/Analytical_I/3%3A_The_Vocabulary_of_Analytical_Chemistry/3.3%3A_Classifying_Analytical_TechniquesAnalyzing a sample generates a chemical or physical signal that is proportional to the amount of analyte in the sample. This signal may be anything we can measure, such as mass or absorbance. It is co...Analyzing a sample generates a chemical or physical signal that is proportional to the amount of analyte in the sample. This signal may be anything we can measure, such as mass or absorbance. It is convenient to divide analytical techniques into two general classes depending on whether the signal is proportional to the mass or moles of analyte, or to the analyte’s concentration.
- https://chem.libretexts.org/Courses/Los_Angeles_Trade_Technical_College/Analytical_Chemistry/2%3A_Analytical_Chemistry_2.0_(Harvey)/11%3A_Spectroscopic_Methods/11.02%3A_Spectroscopy_Based_on_AbsorptionIn absorption spectroscopy a beam of electromagnetic radiation passes through a sample. Much of the radiation passes through the sample without a loss in intensity. At selected wavelengths, however, t...In absorption spectroscopy a beam of electromagnetic radiation passes through a sample. Much of the radiation passes through the sample without a loss in intensity. At selected wavelengths, however, the radiation’s intensity is attenuated. This process of attenuation is called absorption.
- https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Analytical_Chemistry_2.1_(Harvey)/05%3A_Standardizing_Analytical_Methods/5.02%3A_Calibrating_the_SignalThe accuracy in determining kA and Sreag relies on precise signal measurement, using calibrated equipment like balances and spectrophotometers. Calibrating involves adjusting the measured signal, Stot...The accuracy in determining kA and Sreag relies on precise signal measurement, using calibrated equipment like balances and spectrophotometers. Calibrating involves adjusting the measured signal, Stotal, to match a known standard signal, Sstd. For example, balances are calibrated using reference weights, while spectrophotometers are checked by measuring absorbance of specific solutions.
- https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Instrumental_Analysis_(LibreTexts)/17%3A_Applications_of_Infrared_Spectrometry/17.01%3A_Mid-Infrared_Absorption_SpectometryMid-infrared spectrometry is used for the routine qualitative analysis and, to a lesser extent, the quantitative analysis of organic molecules. In this section we consider absorption spectrometry in w...Mid-infrared spectrometry is used for the routine qualitative analysis and, to a lesser extent, the quantitative analysis of organic molecules. In this section we consider absorption spectrometry in which we measure the absorbance of IR light as it passes through a gas, solution, liquid, or solid sample.
- https://chem.libretexts.org/Courses/Northern_Alberta_Institute_of_Technology/CHEM1130_Principles_in_Chemistry_I/4%3A_Chemical_Calculations/4.7%3A_Overview_of_SpectroscopyThe focus of this chapter is on the interaction of ultraviolet, visible, and infrared radiation with matter. Because these techniques use optical materials to disperse and focus the radiation, they of...The focus of this chapter is on the interaction of ultraviolet, visible, and infrared radiation with matter. Because these techniques use optical materials to disperse and focus the radiation, they often are identified as optical spectroscopies. For convenience we will use the simpler term spectroscopy in place of optical spectroscopy; however, you should understand that we are considering only a limited part of a much broader area of analytical techniques.
- https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Instrumental_Analysis_(LibreTexts)/13%3A_Introduction_to_Ultraviolet_Visible_Absorption_Spectrometry/13.4%3A_InstrumentationAs covered in Chapter 7, the basic instrumentation for absorbance measurements consists of a source of radiation, a means for selecting the wavelengths to use, a means for detecting the amount of ligh...As covered in Chapter 7, the basic instrumentation for absorbance measurements consists of a source of radiation, a means for selecting the wavelengths to use, a means for detecting the amount of light absorbed by the sample, and a means for processing and displaying the data. In this section we consider two other essential components of an instrument for measuring the absorbance of UV/Vis radiation by molecules: the optical path that connects the source to the detector and a means for placing t
- https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Instrumental_Analysis_(LibreTexts)/13%3A_Introduction_to_Ultraviolet_Visible_Absorption_Spectrometry/13.03%3A_Effect_of_Noise_on_Transmittance_and_Absorbance_MeasurementsIn absorption spectroscopy, precision is limited by indeterminate errors—primarily instrumental noise—which are introduced when we measure absorbance. Precision generally is worse for low absorbances ...In absorption spectroscopy, precision is limited by indeterminate errors—primarily instrumental noise—which are introduced when we measure absorbance. Precision generally is worse for low absorbances and for high absorbances . We might expect, therefore, that precision will vary with transmittance.
- https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Instrumental_Analysis_(LibreTexts)/07%3A_Components_of_Optical_Instruments/7.01%3A_General_Design_of_Optical_InstrumentsThe spectroscopic techniques in the chapters that follow use instruments that share several common basic components: a source of energy, a means for holding the sample of interest to us, a device that...The spectroscopic techniques in the chapters that follow use instruments that share several common basic components: a source of energy, a means for holding the sample of interest to us, a device that can isolate a narrow range of wavelengths, a detector for measuring the signal, and a signal processor that displays the signal in a form convenient for the analyst.
