Using The Spectrophotometer To Determine The UV Concentration
If the bucket is not properly veiled, the absorption sensitivity to the measurement may be reduced. Knowing the experimental conditions 1 cm cuvette during measurements is important. Buckets designed for a path length of 1 cm are standard and are the most common.
The selection of the bucket is an important element in measuring absorption in the UV-Vis spectrophotometer, as the solutions for analysis are placed in the bucket. In addition, selection is a delicate task because there are several buckets available. Next, it is discussed how different factors influence the selection of the bucket in the UV-Vis spectroscopy system. The next important aspect concerns the measuring wavelengths involved in the application in question. Standard buckets made of PMMA, polystyrene or ordinary glass are only transparent in the visible range. If wavelengths are used in the UV range, below about 300 nm, buckets of quartz glass or a special type of plastic should be used, which provide sufficient transparency in this range.
These buckets are made of Far UV Quartz with a spectral range of 170 to 2700 nm. A bucket for spectrophotometric measurements is a small, transparent rectangular vessel that is available in a variety of materials, quality levels and dimensions. Glass buckets are used for measurements in the visible range of 320 to 2500 nm. Quartz semimers deliver accurate results over the UV and visible range from 200 to 2500 nm. The lower the production tolerance, the better and more repeatable the measurement. Traditional ultraviolet-visible spectroscopy or fluorescence spectroscopy uses liquid samples.
Of course, the solution can concentrate the samples, but it is usually difficult in situations where the sample evaporates or undergoes a chemical change during the concentration process. If the wavelengths in the UV range, below about 300 nm, quartz cells or a special type of plastic are to be used, which provide sufficient transparency in this range. Most experiments with emission absorption spectroscopy question samples that are gases, liquids or solutions. The exception to this are fixed samples that can be mounted on the spectrometer. Gas spectroscopy experiments are usually conducted with long-term cells that are sealed off or through which gas flows. For liquids and solutions, buckets are the most common sample containers.
Buckets made of acrylic plastic or ordinary glass are already absorbed at higher wavelengths. In addition, many of the plastic buckets are not compatible with most organic solvents. If you use a quartz tamper, keep in mind that it is very expensive (~$150 each). If you break it, you’ll have to pay for it, because your lab equipment costs won’t cover these types of losses. The article examines the optical characteristics of such materials that will help you make the right decision before proceeding with absorption measurements.
For photometric measurements of liquid solutions, samples in a predefined format should be placed in the optical light path of a photometer. The default option for this application is buckets, sample containers with 2 or 4 optical transparent windows. This baking material is ideal for use in the visible spectral range and has a decent transmission range of 340 to 2,500 nm. Most applications will fall into the range and many experiments do not need the additional UV range (190 – 340 nm) available with quartz materials.