Toluene has clear absorption peaks at 266 nm and 269 nm. Hexane is only the solvent.
to check the sensitivity of the instrument
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UV light can be used for many widely varied tasks: * Forensics: to indicate the presence of dried bodily fluids. * Entertainment: to make a purple/blue luminescence appear on white or pale materials. * Security: inks which are only visible under UV are used in paper currency and other sensitive documents (visas, passports, etc.) as a proof of validity. * Chemistry: is sometimes used as a method for determining a crystal's structure. * Medicine: controlled UV exposure, sometimes in conjunction with drugs, is an effective treatment for many diseases. * Food processing: UV lamps are used to kill viruses and bacteria in drinking water and in already sealed containers of food. Naturally this list does not include everything that UV light does, but serves as an indicator of the variety and commonality of its use.
All lamps will give off UV but incandescent lamps will give-off unmeasurably small amounts. Discharge lamps essentially all contain mercury and mercury in the discharge gives off UV. However, most lamps are enclosed in UV-absorbing glass, either as primary containment or as an outer enclosure (bulb), so very little gets beyond the outer bulb. If any lamp emits more then almost no UV, it has to be marked (R in the US), and a warning given that it cannot be used in an open fixture - in other words, it must be used behind a UV absorber (usually what is called soft glass - similar to normal window glass).
It is used in UV lamps, paint testes, projection lamps, electronic flashes, xenon arc lamps etc. It is also used in photography and as a general anaesthetic.
Holmium oxide is used as standard reference to check wavelengts.
Erbium has a strong absorption in uv and visible range, It is used in HPlc calibration for the wavelength accuracy verification of the PDA detector.
Potassium dichromate is used in UV calibration as a secondary standard to verify the accuracy of the instrument's wavelength calibration. Its absorption peak at 350 nm is well established, making it ideal for checking the alignment and accuracy of the UV spectrophotometer's wavelength scale. It provides a reference point that helps ensure the instrument is operating correctly for UV measurements.
Potassium chloride is used for calibration of the limit of stray light in UV because it produces a distinct absorption peak around 198 nm, which allows for accurate calibration of the spectrophotometer at this wavelength. This helps to ensure that any stray light present in the UV spectrum can be accurately quantified and minimized during measurements.
Holmium oxide is used in calibration of UV spectrophotometers because it has well-defined absorption peaks at specific wavelengths in the UV range. These peaks can serve as reference points for calibrating the instrument and verifying its accuracy. Holmium oxide provides a reliable and stable reference for wavelength calibration in the UV spectrum.
Kirchhoff's law of calibration (KCL) is used in the calibration of UV-Visible spectrophotometers to ensure accurate measurements of absorbance. It states that the absorbance of a sample is directly proportional to its concentration and path length. By applying KCL during calibration, you can establish a linear relationship between absorbance and concentration, allowing for precise determination of sample concentrations in subsequent measurements.
The solution of potassium chloride is used to evaluate the stray light.
to check the sensitivity of the instrument
Lambda max (λmax) of toluene refers to the wavelength at which toluene exhibits maximum absorbance in UV-Vis spectroscopy. For toluene, λmax is typically around 254 nm, where it absorbs ultraviolet light due to π-π* transitions in its aromatic ring. This property is useful in analytical chemistry for identifying and quantifying toluene in various samples.
Limit of stray light is important in UV calibration to ensure accurate measurements by reducing interference from unwanted light. This is typically done by using optical components that block or absorb stray light, such as filters or baffles. By minimizing stray light, the calibration process can be more precise and reliable.
when prescribed in a monograph record the spectrum of a 0.02 % w/v solution of toluene in hexane the ration of absorbance at the maximum at about 269 nm to that at minimum at about 266 nm is not lessthan 1.5resolution = max abs 269 / min abs 266
Anthracene is used as a calibration standard in High Performance Liquid Chromatography (HPLC) because it has a well-defined retention time and peaks in the UV-visible spectrum, making it easy to detect and quantify. Its consistent behavior helps in determining retention times, resolving power, and column efficiency during method development and troubleshooting in HPLC.