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Introduction to the Visible Spectrophotometer
Published in Paul R. Loconto, Laboratory Experiments in Trace Environmental Quantitative Analysis, 2022
A possible major source of error in spectrophotometric measurement occurs when the path length differs from one sample to the next (i.e. the value for b [see earlier discussion] is different). Hence, two solutions having identical concentrations of a colored analyte (i.e. both a and c are equal) could exhibit different absorbances due to differences in path length b. To minimize this source of systematic error, a cuvette matching exercise is introduced. Cuvette tubes are matched by placing a solution of intermediate absorbance in each and comparing absorbance readings. One tube is chosen arbitrarily as a reference, and others are selected that have the same reading to within 1%. Tubes should always be matched in a separate operation before any spectrophotometric experiments are begun.
2 Thin Film on Glass Substrate
Published in Arpan Deyasi, Pampa Debnath, Asit K. Datta, Siddhartha Bhattacharyya, Photonics, Plasmonics and Information Optics, 2021
SE is a useful non-destructive tool to know the precise sample thickness along with some optical properties of the thin film formed on glass or any other substrate. SE measurement can reveal the change in film thickness and optical properties due to annealing and/or other factors. The model structure considered is air/TiO2/glass to determine the thickness as well as the refractive index. Transmission within the wavelength range of 300–800 nm is measured with spectrophotometer.
Detection — Analytical
Published in Lorris G. Cockerham, Barbara S. Shane, Basic Environmental Toxicology, 2019
Christine A. Purser, Arthur S. Hume
Spectrophotometry is an analytical technique which involves the selective absorption of light by molecules. The energy used in spectrophotometry ranges from the visible wavelength region to the ultraviolet region.
Characterization of the piezoelectric lead zirconate titanate catalyzed degradation of rhodamine B and methylene blue dyes by smartphone-based colorimetry
Published in Instrumentation Science & Technology, 2021
Vishvendra Pratap Singh, Ankit Susaniya, S. C. Jain, Rahul Vaish
A colorimetry method is usually based on a change in the absorbance value of a specific solution for a specific wavelength range. The RGB (red, green, blue) values of the color shifts may be collected by cellphones. Any smartphone with a moderate camera may capture the image that may be characterized using various RGB analysis programs accessible on various internet application stores. The photographs were captured on a Redmi Y3 (Xiaomi) smartphone and the RGB data analyzed using the RGB color picker application. The degradation of MB and RhB was quantified using this method. In addition, a spectrophotometer (Shimadzu UV-2600) was used to verify the measurements. The wavelength of the spectrophotometer is fixed between 400 nm and 800 nm. The peak absorption was recorded at 663 nm and 568 nm for MB and RhB, respectively.
Automated spectrophotometric platform for the quantification of multiple nucleic acid samples
Published in Instrumentation Science & Technology, 2021
Hoon Kang, Sang-Ryoul Park, Ju Hwang Kim, In-Yong Park, Hee-Bong Yoo, Inchul Yang, Haewon Jung
A spectrophotometer based on the Beer–Lambert law measures the absorbance of a chemical substance by comparing the relative intensity of light before and after it passes through a sample solution. In recent years, it has been widely used in a variety of fields, such as medical science, medicine, chemistry, and food science due to its simplicity and ease of use.[1–4] In particular, it has been commonly utilized as a screening instrument in the field of biomolecular analysis to estimate the concentration of unknown nucleic acid samples.[5–13] In addition, it can be useful in the study of the interaction of nanomaterials with nucleic acids.[14–17]
The effects of CO2 laser treatment on a digital velvet printing
Published in The Journal of The Textile Institute, 2021
To measure the interaction between a chemical compound such as dye or pigment on a textile sample and electromagnetic radiation, spectroscopy or spectrochemical analysis can be used (Choudhury, 2014a). Spectrophotometers illuminate a sample to measure the amount of light that is reflected or transmitted at discrete wavelengths. The color of the material is determined by the amount of light reflected throughout the visible range of the spectrum (Choudhury, 2014a). The range of wavelengths of visible light is from 380 to 780 nm in the human system of vision, with red having the longest wavelength of 780 nm with the lowest frequency. The shortest wavelength of about 380 nm with the highest frequency is the color violet.