Does measuring visible absorption spectrum detect impurities?
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38 Citations | The plate obtained is suited to the detection of detailed structure of absorption spectra and, by use of a reference spectrum, to the quantitative estimation of absorption. |
01 Sep 1990 8 Citations | The results for the absorption spectrum of pure water throughout the visible compare favorably with accepted values. |
| EXPERIMENTAL General The instrument is generally applicable to absorption measurements in the visible spectrum. | |
88 Citations | This absorption spectrum will be useful... |
| The technique is suitable for measuring effective absorption coefficients from 10(3) to 10(5) cm(-1). | |
48 Citations | For narrow absorption features and non-congested spectra this approach does not even require a zero-absorption measurement with the empty cavity. |
21 Citations | The calculated absorption spectrum and its absolute intensity are in good agreement with the experimental results. |
| If these absorption peaks are broadened and are superimposed on each other, the absorption spectrum observed experimentally can be reproduced. | |
| Above all, this method could be adapted to samples of strong absorption in the visible region. |
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What are the different methods for trace analysis of genotoxic impurities?5 answersThere are several methods for trace analysis of genotoxic impurities. One method involves using liquid chromatography-mass spectrometry (LC-MS) to determine potential genotoxic impurities in drug substances. For example, DasameswaraRao et al. developed an LC-MS method to determine three potential genotoxic impurities in quetiapine fumarate. Another method is gas chromatography-mass spectrometry (GC-MS), which was used by Maniavannan et al. to analyze sulfonate esters in teneligliptin. LC-MS can also be used for trace analysis of genotoxic impurities in specific compounds. Hoang and Aldridge developed LC-MS methods for trace analysis of genotoxic impurities in Ivacaftor and Lumacaftor. Jie proposed a liquid chromatography method for detecting potential genotoxic impurities in a compound containing a benzimidazole structure. Additionally, a method using high performance liquid chromatography (HPLC) was developed by Xiang et al. for detecting trace genotoxic impurities in voriconazole. These methods provide reliable and sensitive techniques for the analysis of genotoxic impurities in various compounds.
How to measure the visible light absorb by photocatalyst?5 answersVisible light absorption by photocatalysts can be measured using opto-electronic devices that combine the measurement of absorbed light with quantitative chemical analysis of the products. These devices utilize high power visible LEDs as convenient light sources without the need for spectral filtering. The LED output can be efficiently imaged into the sample, and the residual transmitted light can be continuously monitored by a calibrated solar cell. Another approach is to use an Rz Photocatalyst Activity Indicator Ink to assess the photocatalytic activity of powdered semiconductor photocatalysts under visible light. Additionally, local probing of the optical properties can provide insights into the visible light absorption of mixed metal oxide interfaces in photocatalysts. Grinding photocatalysts with an ammonium carbamate additive can also result in a shift of light absorption towards the visible region.
How can impurities on transparent surfaces be measured?5 answersImpurities on transparent surfaces can be measured using various methods. One approach is to use multi-wavelength incident light to measure the parameters of transparent objects based on the birefringence model. Another method involves using a line-shaped detector arrangement for electromagnetic radiation to detect contamination on curved transparent substrates. Equipment for detecting impurities in transparent material can also utilize a light source, camera, and signal-processing apparatus to process and analyze signals representing light transmission through the material. Additionally, impurities in cylindrically shaped transparent media can be detected by illuminating the medium with electromagnetic radiation and analyzing the components of the radiation received by a detector at multiple relative angular positions. A method for detecting impurities in transparent material involves scanning the material line by line and comparing the light transmission with a reference value, followed by analyzing the transmission values in the central area of the impurity to determine its extent and shape.
How can impurities on transparent surfaces be quantified?5 answersImpurities on transparent surfaces can be quantified using various methods. One approach is to use a device that includes a source of electromagnetic radiation and a line-shaped detector arrangement. This device allows for the quantitative detection of contaminants on curved transparent surfaces, such as drinking glasses. Another method involves equipment that uses a light source to illuminate the material and a camera to detect the light transmitted through the material. Signal-processing apparatus is then used to process and analyze the signals from the camera, allowing for the quantification of impurities in the transparent material. Additionally, a method and system are described that involve scanning the material line by line and comparing the light transmission through the material with a reference value. This allows for the detection and analysis of impurities, including determining their extent and shape.
How to detect impurities of seed by Nir spectroscopy ?5 answersNear infrared spectroscopy (NIR) can be used to detect impurities in seeds. The process involves collecting NIR spectra of standard seed cotton samples, calculating the first derivative spectrum, removing zero values, and binarizing the spectrum. Parameters of spectral characteristic peaks are then calculated and used to establish a database. When a seed cotton sample needs to be detected, its NIR spectrum is collected, and the same steps of calculating the first derivative spectrum, removing zero values, and binarizing are followed. The similarity between the spectrum of the sample and the standard seed cotton samples is calculated, and the model and database information corresponding to the highest similarity are used for analysis. This method allows for the identification of impurities in the seed cotton sample.
Citations:Zhou Wanhuai, Liu Congjiu, Xu Shoudong, Liang Houjun, Chen Yue, Zhang Xiaomin
How to detect of impurities of seeds ?5 answersImpurities in seeds can be detected using various methods and devices. One method is the use of a screening device that removes impurities from rice seeds. This device consists of a centrifugation component, a blocking component, and a sorting component, which work together to separate impurities from the seeds. Another method is the use of a seeds detector, which is a device that samples the seeds and detects impurities. The seeds detector has a handle with a sample spoon covered with a spoon filter net, allowing for accurate sampling. Additionally, an automatic grading machine can be used to remove impurities from grain seeds. This machine utilizes a rotary body, a screen, a maple leaf wheel, and other components to achieve one-step screening, impurity removal, and grading of various particle seeds. Experimental research has also been conducted to measure the quality of impurity separation in grain seeds using a gravimetric separator with mechanical shaker and an aspiration installation. Overall, these methods and devices provide effective ways to detect and remove impurities from seeds.