TLC scanners are instruments for the quantitative detection and analysis of thin-layer chromatography. There are currently two types of TLC scanners on the market:
The traditional TLC scanner is a full-wavelength scanner that provides a selectable wavelength in the range of 200-800 nm. The substance is determined by detecting the absorption of light by the sample. The scanner is also capable of detecting the fluorescence intensity produced by UV radiation at 254 nm or 365 nm for specific detection.
TLC scanners are divided into single beam scanning thin layer chromatography scanners, dual beam scanning thin layer chromatography scanners and dual wavelength scanning thin layer chromatography scanners.
Single beam scanning: Using a single beam (ie, single wavelength scanning), the result is a single curve at a particular wavelength in the above image. The instrument is simple in structure, but the baseline is unstable and rarely used in practice.
Dual beam scanning: two beams of the same wavelength are scanned synchronously, one beam scans the sample to expand the channel, and the other beam scans the blank area beside the sample channel, so that the blank absorption can be deducted, and the uneven layering of the thin plate expansion direction is partially eliminated. Error. However, it is impossible to eliminate the error caused by the unevenness of the plating in the unfolding direction.
Dual-wavelength scanning: two different wavelengths of light alternately scan the channel area where the sample is unfolded. When the wavelength is selected, one wavelength is the maximum absorption position of the sample, and the other is the position of the absorption minimum. As shown in the figure above, if the detection target is 3 (the maximum absorption peak is 290 nm, the minimum value is 200 nm, 260 nm or 325 nm). This method can basically eliminate the error caused by uneven plating, so the scanning baseline is very stable.
Among the above various scanning methods, according to the size of the light source (scanning accuracy), it can be divided into a linear scanning thin layer chromatography scanner and a sawtooth scanning thin layer chromatography scanner.
Straight line scan: sweeps the entire expansion channel with a wide beam that covers the sample expansion channel, ie in the unfolding direction (the abscissa in the figure), the data for each point is just a scan data point.
Sawtooth scanning: With a point source, the spot size is smaller than the channel width, so when moving to any point in the unfolding direction, the light source is scanned point by point along the direction of the sample channel, ie forming a "shape" (or zigzag scan). Thus, the data for each point in the unfolding direction is the accumulated value of the plurality of dot scan results. The accuracy of the sawtooth scan is significantly improved relative to the linear scan.
Currently, in quantitative analysis, thin-layer scanning uses multi-wavelength sawtooth scanning.
Http://?tid=1463 400-1158-566
Http://
Http://
Insulin Syringes Needle,Disable Syringe,Monoject Syringe,10 Ml Syringe
FOSHAN PHARMA CO., LTD. , https://www.fs-pharma.com