10 Questions
What is the primary function of a spectrophotometer?
to measure and analyze the spectrum of samples
What type of spectrophotometer is used to measure the material of absorbance and quantitative analysis at visible or ultraviolet light?
UV-VIS spectrophotometer
What type of spectrophotometer is used to measure absorbance and conduct quantitative analysis at visible light?
VIS spectrophotometer
What is the primary difference between a single beam and split beam UV spectrophotometer?
The number of beams used to measure light intensity
What is the purpose of a cuvette in a single beam spectrophotometer?
To hold the reference and sample solutions
What is the main limitation of a single-beam UV-visible spectrophotometer in pharmaceutical and quality inspection industries?
It is not suitable for high demanding pharmaceutical and quality inspection industries.
What is the main advantage of a double-beam UV-visible spectrophotometer?
It can measure high-concentration samples, multi-component mixed samples, and perform better in turbid samples with more sensitivity than the single beam machine.
How does a split-beam UV-visible spectrophotometer work?
The light emitted by the same monochromator is split into two beams, one of which reaches the detector directly and the other passes through the sample and reaches the other detector.
What is the main characteristic of infrared spectroscopy?
It is fast, requires low sample volume (a few micrograms to a few milligrams), and has strong characterization (various substances have their own specific infrared spectrum).
What is the main difference between a UV/VIS absorption spectrophotometer and a fluorescence spectrophotometer?
A UV/VIS absorption spectrophotometer detects light that has passed directly through the sample, while a fluorescence spectrophotometer detects fluorescent light emitted in the 90° direction.
Study Notes
Spectrophotometers
- Spectrophotometers are instruments that measure and analyze the spectrum of samples.
- They can be divided into five subcategories according to the wavelength and application context.
Types of Spectrophotometers
- VIS Spectrophotometer: measures absorbance and conducts quantitative analysis at visible light (400 ~ 760nm).
- UV-VIS Spectrophotometer: measures material absorbance and conducts quantitative analysis at visible or ultraviolet light (200 ~ 760nm).
- Infrared Spectrophotometer: analyzes samples in various conditions (gas, liquid, solid) using infrared spectrum greater than 760nm.
- Fluorescence Spectrophotometer: depends on the analysis of fluorescence light and can be used in fields like chemistry, medicine, and pharmacy.
- Atomic Absorption Spectrophotometer: (no specific details provided)
VIS Spectrophotometer
- Used to measure bacterial cell density at 600 nm.
UV-VIS Spectrophotometer
- Can measure nucleic acid and protein concentrations and bacterial cell density.
- Divided into three types: Single Beam, Double Beam, and Split Beam.
Single Beam UV-VIS Spectrophotometer
- Uses a single beam of monochromatic light to measure light intensity.
- Consists of a light source, optical parts, absorption cell, cuvette, and photoelectric converter.
- Not suitable for high-demanding pharmaceutical and quality inspection industries.
Double Beam UV-VIS Spectrophotometer
- Utilizes two monochromators to measure two different wavelengths of monochromatic light.
- Can measure high-concentration samples, multi-component mixed samples, and perform better in turbid samples.
Split Beam UV-VIS Spectrophotometer
- Splits the light emitted by a monochromator into two beams.
- Monitors errors in the light source, but does not eliminate the effects of the reference.
Infrared Spectrophotometer
- Fast, low sample volume (a few micrograms to a few milligrams), and strong characterization.
- Can analyze a variety of conditions (gas, liquid, solid) of the sample.
Fluorescence Spectrophotometer
- Depends on the analysis of fluorescence light.
- Similar to an UV/VIS absorption spectrophotometer, but detects fluorescent light emitted in the 90° direction.
- Passed through an emission monochromator (emission spectroscopy).
Learn about the different types of spectrophotometers, including VIS, UV-VIS, Infrared, Fluorescence, and Atomic Absorption, and their applications in various fields.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
