A spectrophotometer is an instrument that uses spectrophotometry to quantitatively and qualitatively analyze substances. Shoulder bag, crossbody bag, hand bag, mommy bag,Hiking bag,Thermal box Dongguan Jinying Handbags Co.,Ltd , https://www.jinyingnicebag.com
The spectrophotometric method is to determine the qualitative and quantitative analysis of the substance by measuring the absorbance of the measured substance at a specific wavelength or within a certain wavelength range. Commonly used wavelength ranges are: (1) 200-400nm ultraviolet region, (2) 400-760nm visible region, (3) 2.5-25μm (4000cm <-1> ～ 400cm <-1> in terms of wave number) Infrared zone. The instruments used are ultraviolet spectrophotometer, visible spectrophotometer (or colorimeter), infrared spectrophotometer or atomic absorption spectrophotometer. In order to ensure the precision and accuracy of the measurement, all instruments should be regularly calibrated in accordance with the national metrological verification regulations or the provisions of this appendix. When the monochromatic light radiation passes through the solution of the substance to be measured, the amount absorbed by the substance is proportional to the concentration of the substance and the thickness of the liquid layer (optical path length). The relationship is as follows:
A = -log (I / I.) =-LgT = kLc
In the formula: A is absorption;
Is the intensity of the incident monochromatic light;
Is the intensity of the transmitted monochromatic light;
T is the transmittance of the substance;
k is the absorption coefficient;
L is the optical path of the analyte
c is the concentration of the substance
Simple principle of spectrophotometer
The spectrophotometer uses a light source that can generate multiple wavelengths. A series of spectroscopic devices are used to generate a light source of a specific wavelength. After the light source passes through the tested sample, part of the light source is absorbed, and the absorbance value of the sample is calculated to be converted into the concentration of the sample. . The absorbance of the sample is proportional to the concentration of the sample.