A spectrophotometer is an analytical instrument that measures the intensity of light absorbed, transmitted, or reflected by a chemical substance as a function of wavelength. It quantifies concentrations in liquids, plastics, or fabrics, primarily using UV-visible light to analyze samples. Essential for chemical analysis, color measurement, and quality control, it works by passing light through a sample to determine its concentration via Beer-Lambert’s law

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Key Components and Working Principle

• Light Source: Emits light, typically using tungsten (visible) or deuterium (UV) lamps.
• Monochromator (Prism/Grating): Separates white light into distinct wavelengths, allowing selection of a specific wavelength to hit the sample.
• Sample Holder (Cuvette): Holds the sample, usually liquid, with quartz cuvettes used for UV light.
• Detector: Measures the light intensity after it passes through the sample, converting this data into absorbance or transmittance values. 

Key Applications and Uses

• Quantitative Analysis: Determines the concentration of unknown solutes in a solution based on absorbance levels.
• Color Control: Used by manufacturers to ensure color consistency in products like paint, textiles, and plastics.
• Research & Laboratory: Utilized in biochemistry, environmental testing, and pharmaceutical industries for analyzing molecular species.
• Spectrophotometer Types: Available as single-beam (measures one sample at a time) or double-beam (measures sample and reference simultaneously).