spectrophotometer
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A multichannel kinetic spectrophotometer-fluorimeter with pulsed measuring beam and differential optics has been constructed for measurements of light-induced absorbance and fluorescence yield changes in isolated chlorophyll-proteins, thylakoids and intact cells including algae and photosynthetic bacteria. The measuring beam, provided by a short (2 micros) pulse from a xenon flash lamp, is divided into a sample and reference channel by a broad band beam splitter. The spectrum in each channel is analyzed separately by a photodiode array. The use of flash measuring beam and differential detection yields high signal-to-noise ratio (noise level of 2 x 10(-4) in absorbance units per single flash) with negligible actinic effect. The instrument covers a spectral range between 300 and 1050 nm with a spectral resolution of 2.1, 6.4 or 12.8 nm dependent on the type of grating used. The optical design of the instrument enables measuring of the difference spectra during an actinic irradiation of samples with continuous light and/or saturation flashes. The time resolution of the spectrophotometer is limited by the length of Xe flash lamp pulses to 2 micros.
- MeSH
- hořčík analýza MeSH
- lidé MeSH
- spektrofotometrie atomová přístrojové vybavení metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- hořčík MeSH
OBJECTIVE: The aim of this study was to compare the visual assessment of tooth shade with the measurement using intraoral scanner (IOS) and spectrophotometer devices. METHODOLOGY: The colour for a single unit implant supported crown was measured visually, using IOS, and spectrophotometer. The results of the digital methods were compared with the visual measurement. RESULTS: A complete colour match with the visual measurement was in 42.9% of cases for IOS, and in 33.3% of cases for spectrophotometry. The match in the colour value, hue, and chroma were in 61.9%, 95.2%, and 66.7% of cases, respectively, for the IOS; and in 61.9%, 61.9%, and 66.7% of cases, respectively, for the spectrophotometry. The differences between the IOS and spectrophotometry were not statistically significant. CONCLUSIONS: The most reliable method for tooth colour selection is the visual measurement by an experienced dentist. IOS and spectrophotometer can be used as an alternative method, however in both cases they should be verified using visual measurement.
- Klíčová slova
- colour match, intraoral scanner, spectrophotometer, visual match,
- MeSH
- barva MeSH
- barvení protéz * metody MeSH
- keramika MeSH
- spektrofotometrie MeSH
- vnímání barev * MeSH
- Publikační typ
- časopisecké články MeSH
A hand-held near infrared (NIR) spectrophotometer combined with a similarity index (SI) method was evaluated to identify meat samples sourced from exotic and traditional meat species. Fresh meat cuts of lamb (Ovis aries), emu (Dromaius novaehollandiae), camel (Camelus dromedarius), and beef (Bos taurus) sourced from a commercial abattoir were used and analyzed using a hand-held NIR spectrophotometer. The NIR spectra of the commercial and exotic meat samples were analyzed using principal component analysis (PCA), linear discriminant analysis (LDA), and a similarity index (SI). The overall accuracy of the LDA models was 87.8%. Generally, the results of this study indicated that SI combined with NIR spectroscopy can distinguish meat samples sourced from different animal species. In future, we can expect that methods such as SI will improve the implementation of NIR spectroscopy in the meat and food industries as this method can be rapid, handy, affordable, and easy to understand for users and customers.
- Klíčová slova
- NIR, chemometrics, exotic species, meat, similarity index,
- Publikační typ
- časopisecké články MeSH
The newly developed IMU-LA-TEST ROTA Dot-ELISA kit manufactured in cooperation by Lachema Brno and VUVeL Brno for detection of viral proteins of the inner and outer capsid proved suitable for the rapid virological diagnosis of rotaviruses group A. The advantages of the method are that it is simple and unpretentious and does not require the use of a spectrophotometer. For comparison ROTA-ELISA Bioveta, ROTALEX Orion and PAGE were used.
- MeSH
- ELISA přístrojové vybavení MeSH
- lidé MeSH
- rotavirové infekce diagnóza MeSH
- virové proteiny analýza MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- anglický abstrakt MeSH
- časopisecké články MeSH
- Názvy látek
- virové proteiny MeSH
In the present paper, discussion has been focused upon the problem of identifying toxic substances with the aid of the GC/MS system, i.e. gas chromatography - mass spectrometry. Factors involved in a successful combination of a gas chromatography with a mass spectrophotometer have been pointed out. In addition attention has been drawn to the two various ways of obtaining the spectra, i.e. the classic EI spectra and those obtained during chemical ionization, the mode of performing mass fragmentography and, last, the importance and characteristic features of the computer-controlled GC/MS systems.
- MeSH
- chromatografie plynová * přístrojové vybavení metody MeSH
- hmotnostní spektrometrie * přístrojové vybavení metody MeSH
- léčivé přípravky analýza metabolismus MeSH
- lidé MeSH
- soudní lékařství MeSH
- toxikologie * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- anglický abstrakt MeSH
- časopisecké články MeSH
- Názvy látek
- léčivé přípravky MeSH
This thesis deals with testing of inhibition activity beta-carboline alkaloids on activity of enzymes acetylcholinesterase (ACHE) and butyrylcholinesterase (BUCHE) using test "Fast Blue B salt" at TLC desk and Ellman's test using spectrophotometer. It was also investigated how dimethylsulfoxide used as a solvent in combination with water affects activity of enzymes and alkaloids. Results show harmine in form of base and salt in water and in mixture of DMSO and water has the hightest inhibition activity on ACHE using eserine as reference substance. Harmalol in form of salt in water and harmine in form of base and salt in mixture of DMSO and water has the hightest activity on BUCHE. It was find out that DMSO considerably affects activity of enzymes and alkaloids.
- MeSH
- acetylcholinesterasa metabolismus MeSH
- alkaloidy farmakologie MeSH
- butyrylcholinesterasa metabolismus MeSH
- cholinesterasové inhibitory farmakologie MeSH
- dimethylsulfoxid farmakologie MeSH
- karboliny farmakologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- acetylcholinesterasa MeSH
- alkaloidy MeSH
- butyrylcholinesterasa MeSH
- cholinesterasové inhibitory MeSH
- dimethylsulfoxid MeSH
- karboliny MeSH
This study monitored the influence of milk samples temperature on the measuring accuracy of FT-NIR spectroscopy in milk content analysis. Reference methods were used to determine dry matter, fat, protein, and lactose content in cow's milk. Milk samples were measured in reflectance mode on an integrating sphere with the use of a compression cuvette and a transflectance cuvette, ensuring a beam trajectory length of h = 0.2 mm. The samples were measured at 18, 20, 22, 24, and 40°C, and analyses were performed at 100 scans at a resolution of 8 cm-1. The measurements were influenced by the temperatures of the samples during the evaluation of all analyzed constituents (P < 0.05). Our results confirmed that the accurate determination of milk constituents requires maintaining, during analysis, the temperature conditions of the samples and the conditions for which the spectrophotometer calibration was designed.
- MeSH
- blízká infračervená spektroskopie metody MeSH
- diskriminační analýza MeSH
- laktosa analýza MeSH
- mléčné bílkoviny analýza MeSH
- mléko chemie MeSH
- správnost dat * MeSH
- teplota * MeSH
- triglyceridy analýza MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- laktosa MeSH
- mléčné bílkoviny MeSH
- triglyceridy MeSH
In this contribution, we propose a novel functional surface-enhanced Raman spectroscopy (SERS) platform for the detection of one of the most hazardous heavy metal ions, Hg2+. The design of the proposed sensor is based on the combination of surface plasmon-polariton (SPP) supporting gold grating with the high homogeneity of the response and enhancement and mercaptosuccinic acid (MSA) based specific recognition layer. For the first time, diazonium grafted 4-ethynylphenyl groups have undergone the sunlight-induced thiol-yne reaction with MSA in the presence of Eosine Y. The developed SERS platform provides an extremely sensitive, selective, and convenient analytical procedure to detect mercury ions with limit of detection (LOD) as low as 10-10 M (0.027 µg/L) with excellent selectivity over other metals. The developed SERS sensor is compatible with a portable SERS spectrophotometer and does not require the expensive equipment for statistical methods of analysis.
- Klíčová slova
- Hg2+ sensors, SERS, surface modification, water analysis,
- Publikační typ
- časopisecké články MeSH
Precise quantification and quality characterisation of isolated RNAs are prerequisites for their further exploitation in genome-wide microarrays, Northern blots, cDNA library preparation and others. Our data indicate that RNA analyses using Agilent RNA Nano Assay exhibit several advantages when compared with those performed on ethidium bromide-stained agarose gel electrophoresis or on a spectrophotometer. The RNA Nano Assay makes it possible to estimate RNA concentrations in the range from 1000 ng microl(-1) to 17 ng microl(-1). The presence of impurities including traces of DNA within RNA samples does not influence the concentration measurements. Like agarose gel electrophoresis, RNA Nano Assay allows to analyse RNAs dissolved in formamide and therefore protected against RNase action. Moreover, it allows a clearer distinction of partially degraded samples. The limitation of RNA Nano Assay is the impossibility to detect and to analyse double-stranded RNAs.
- MeSH
- elektroforéza v agarovém gelu metody MeSH
- exprese genu genetika MeSH
- fungální RNA analýza MeSH
- polymerázová řetězová reakce přístrojové vybavení metody MeSH
- reagenční diagnostické soupravy * MeSH
- Saccharomyces cerevisiae genetika MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
- Názvy látek
- fungální RNA MeSH
- reagenční diagnostické soupravy * MeSH
