WO2016206355A1

WO2016206355A1 - Ultraviolet capillary column detector based on ccd

Info

Publication number: WO2016206355A1
Application number: PCT/CN2016/070112
Authority: WO
Inventors: 阎超; 茹鑫; 李静; 刘元元; 阚文彬; 祝文君; 万青云
Original assignee: 阎超
Priority date: 2015-06-23
Filing date: 2016-01-05
Publication date: 2016-12-29
Also published as: CN104931636B; CN104931636A

Abstract

An ultraviolet capillary column detector based on CCD comprises an ultraviolet capillary column chromatographic separation system (1100), a CCD chromatography and spectrum detector (1200) and a linkage control PC (1300). The ultraviolet capillary column chromatographic separation system (1100) is connected with the CCD chromatography and spectrum detector (1200), the linkage control PC (1300) is in controlled connection with the ultraviolet capillary column chromatographic separation system (1100) and the CCD chromatography and spectrum detector (1200), and the CCD chromatography spectrum detector (1200) comprises a nanoliter detection cell (1210), a detection light source (1220), a CCD spectrograph (1230), a guide-in optical fiber (1240) and a receiving optical fiber (1250). The ultraviolet capillary column detector based on CCD is good in the consistency of indicators and high in sensitivity, and has the characteristics of low power consumption, high resolution, high read-out rate, low cost and miniature size; thus, a new and efficient detection means is provided for the chromatography field, information regarding the chromatography and spectrum of the sample can be obtained at the same time in one operation, a large amount of time and costs of chromatographic analysis are saved, and the detector is more advantageous for analyzing complex samples, such as biological samples, medicinal samples and food samples.

Description

CCD-based UV capillary column detector

Technical field

The invention relates to a multi-wavelength ultraviolet visible light detector, in particular to a CCD based ultraviolet capillary column detector.

Background technique

The multi-wavelength UV-Vis detector in liquid chromatography responds to most of the substances with UV-visible absorption, and works stably under various conditions and has a wide linear operating range. The multi-wavelength UV-Vis absorption detector is capable of simultaneously measuring chromatographic signals at multiple wavelengths to identify peaks and determine peak purity.

At present, the most common multi-wavelength detector applied to chromatography in the world is a Diode array detector (DAD or PDA). The DAD detector uses a linear arrangement of multiple photodiodes. Due to the limitation of process and pixel size, the number of DAD units is not high and the spectral resolution is relatively limited. On the other hand, the data acquisition workload is very large, for electronics. The system requirements are higher.

Summary of the invention

Based on this, in view of the above technical problems, a CCD-based ultraviolet capillary column detector is provided.

In order to solve the above technical problem, the present invention adopts the following technical solutions:

A CCD-based ultraviolet capillary column detector, comprising an ultraviolet capillary column chromatography system, a CCD chromatographic detector, and a linkage control PC, wherein the ultraviolet capillary column chromatography system is connected to a CCD chromatographic detector, The linkage control PC is connected to the ultraviolet capillary column chromatography system and the CCD chromatographic detector, and the CCD chromatographic detector comprises a nano-up detection cell, a detection light source, a CCD spectrometer, an introduction fiber, and a receiving fiber. The upgrade detection pool has a rectangular pool cavity, and the four sides of the nanometer detection pool have ten Four channels extending in a word and communicating with the cell cavity, the detection light source and the CCD spectrometer are respectively connected to one end of the introduction fiber and the receiving fiber, and the other ends of the introduction fiber and the receiving fiber respectively extend through the channel In the cell cavity, a capillary chromatography column of the chromatographic separation system on the outer capillary column protrudes into the cell cavity and intersects with the introduction fiber and the receiving fiber cross, and the detection window of the capillary column is located in the three At the intersection of the cross, the CCD spectrometer is also connected to the linkage control PC.

The nano-upgrading detection pool includes a metal base and an upper buckle cover, the metal base has a pool groove in a middle portion thereof, and the four channels are located at the metal base, and the entrance of the channel has a fixed introduction fiber, a receiving fiber, and a capillary tube The Peek nut of the column, the four corners of the upper cover are fixed to the metal base by an M4 hexagon socket head screw, and the upper cover covers the pool to form the pool cavity.

The middle portion of the upper buckle cover has a viewing port, and the M4 slotted flat end set screw is disposed in the observation port.

The ultraviolet capillary column chromatography system includes two high pressure pumps, a micro flow mixing valve, an automatic sampler, a quantitative injection valve, a four-way diverter valve, a back pressure valve, a capillary column, a buffer bottle, a restriction valve, and a high-pressure power source, the two high-pressure pumps are connected to the micro-flow mixing valve, and the micro-flow mixing valve is connected to the quantitative injection valve via the automatic sampler, and four ports of the four-way diverter valve are respectively connected The quantitative injection valve, the positive electrode of the high-voltage power source, the back pressure valve, and the inlet end of the capillary column, the outlet end of the capillary column is connected to the restrictor valve, and the buffer bottle has a buffer solution therein. The restrictor valve is connected to the buffer, and a negative electrode of the high voltage power source is connected to the buffer.

The tank has a rubber mat covering the introduction fiber and the receiving fiber.

The detection light source is a xenon lamp.

The detection window is a quartz window.

The invention has simple operation, stable performance, good index consistency and high sensitivity, and the invention is based on CCD, has the characteristics of low power consumption, high resolution, high readout rate, low cost, and miniaturization, and provides the chromatographic field. A new and efficient detection method, the combination of the UV capillary column chromatography system and the CCD chromatographic detector helps to improve the sensitivity of the CCD detector, and simultaneously obtains the sample chromatogram and spectrum information in one operation. Save a lot of chromatographic analysis The time and cost of the analysis of complex samples such as organisms, drugs, foods and more.

DRAWINGS

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments:

1 is a schematic structural view of a module of the present invention;

Figure 2 is a schematic view of the structure of the present invention;

3 is a schematic structural diagram of a nano upgrade detection pool of the present invention;

4 is a spectrum diagram of a xenon lamp of an experiment according to an embodiment of the present invention;

Figure 5 is a chromatogram of separation of naphthalene and anthracene according to an experiment of the present invention;

Figure 6 is a three-dimensional full-wavelength scan of naphthalene and anthracene experimentally conducted in accordance with an embodiment of the present invention.

detailed description

As shown in Fig. 1, a CCD-based UV capillary column detector includes an ultraviolet capillary column chromatography system 1100, a CCD chromatographic detector 1200, and a linkage control PC1300, and an ultraviolet capillary column chromatography system 1100 and CCD chromatography. The spectrum detector 1200 is connected, and the linkage control PC1300 is connected with the ultraviolet capillary column chromatography system 1100 and the CCD chromatographic spectrum detector 1200 to realize the whole-disk automation combined control of the ultraviolet capillary column chromatography system 1100 and the CCD chromatography spectrum detector 1200. .

CCD (charge-coupled device) is a photosensitive detection element based on metal-oxide-semiconductor technology. Its biggest feature is the charge as a signal, rather than the common voltage or current signal. The whole process is Generation, storage, transmission and detection of charge. The CCD array detector is an optical multi-channel detector developed based on charge coupled devices. Since the invention of the BELL laboratory in the early 1970s, CCD has received a lot of attention because of its extremely high sensitivity, wide spectral response range and dynamic range. Compared with common photomultiplier tubes (PMT), photodiode array (PDA) and charge injection devices (CID), CCD has a wide spectral response range, low detection limit, high quantum efficiency and wide dynamic range. Low dark current and readout noise, small manufacturing size, low power consumption and simultaneous detection of multiple channels. At present, CCD has been widely used in imaging, surveillance systems, astronomical observation, military and spectral analysis. For example, the famous Hubble Space Telescope uses CCD The technology performs optical imaging. The application of CCD in the field of analysis begins with the field of spectrum analysis. CCD-AES based on CCD technology, CCD-ICP-AES and other spectral detection studies have been widely carried out, achieving simultaneous detection of multiple elements, and also obtaining spectral background.

The combination of the UV capillary column chromatography system 1100 and the CCD chromatographic detector 1200 helps to increase the sensitivity of the CCD chromatographic detector 1200, and simultaneously obtains sample chromatogram and spectral information in one operation, saving a large amount of chromatographic analysis. The time and cost of the analysis of complex samples such as organisms, drugs, foods and more.

As shown in FIG. 2, the ultraviolet capillary column chromatography system 1100 includes two high pressure pumps 1110, a micro flow mixing valve 1120, an automatic sampler 1130, a quantitative injection valve 1140, a four-way diverter valve 1150, a back pressure valve 1160, and a capillary tube. Column 1170, buffer bottle 1180, restrictor valve 1190, and high voltage power source 1198.

Two high pressure pumps 1110 are respectively connected to two solvent bottles 1199, and the other end is connected to the micro flow mixing valve 1120. The micro flow mixing valve 1120 is connected to the quantitative injection valve 1140 via the automatic sampler 1130, and the four ports of the four-way diverter valve 1150 are connected. The quantitative injection valve 1140, the positive electrode of the high voltage power supply 1198, the back pressure valve 1160, and the inlet end of the capillary column 1170 are respectively connected. The outlet end of the capillary column 1170 is connected to the restriction valve 1190, and the buffer bottle 1180 has a buffer. The restrictor valve 1190 is connected to the buffer, and the negative electrode of the high voltage power source 1198 is connected to the buffer.

Among them, the buffer is determined according to the type of mobile phase in the experimental system.

The high pressure pump 1110 can ensure that the liquid in the solvent bottle 1199 passes through the capillary column 1170 under the action of hydraulic pressure, can stably deliver the flow of the Bainer upgrade, and can realize the gradient program adjustable, and can effectively suppress the separation system under the action of high pressure. The generation of bubbles.

The micro-flow mixing valve 1120 can realize the gradient mixing of the binary solvent, and the gradient of the gradient is suppressed while ensuring the mixing efficiency, thereby ensuring the accuracy and reproducibility of the analysis. Maintaining a constant column front pressure at the front end of the separation capillary column 10 is the key to the stability of the system. The solvent is pumped by the high pressure pump 1110 in the form of a constant current, and is driven in the form of a constant pressure at the four-way diverter valve 1150, through the four-way split. Valve 1150 and back pressure valve 1160 cooperate to effect pressure driving of the solvent and sample into capillary column 1170. The function of the restrictor valve 1190 is to maintain a certain pressure at the outlet end of the capillary column 1170, thereby suppressing the formation of bubbles caused by sudden changes in pressure and ensuring the stability of the system.

The autosampler 1130 can perform high rate injection and multi-class analysis processing, which is used for injection. Needle, valve and other flow path materials are carefully considered and needle cleaning is provided to minimize cross-contamination (residue) and the aspirated sample is pushed into the quantitative injection valve 1140 with an external loop The way to ensure the accuracy and accuracy of the injection.

The high-voltage power source 1198 increases the electroosmotic flow on the basis of the pressure flow, so that the pressure and electric field of the solvent and the sample in the capillary column 1170 are simultaneously driven and rapidly separated. The positive electrode is connected to the four-way diverter valve 1150, and the negative electrode is inserted into the buffer of the buffer bottle 1180, and a positive and negative voltage can be freely applied across the capillary column 1170.

Specifically, the CCD chromatographic spectrum detector 1200 includes a nanoscale detection pool 1210, a detection light source 1220, a CCD spectrometer 1230, an introduction fiber 1240, and a receiving fiber 1250.

As shown in FIG. 3, the nano-upgrade detection pool 1210 has a rectangular pool cavity, and four sides of the nano-upgrade detection pool have four channels that are cross-shaped and communicate with the cell cavity.

The detecting light source 1220 and the CCD spectrometer 1230 are respectively connected to one end of the introduction optical fiber 1240 and the receiving optical fiber 1250, and the other end of the introduction optical fiber 1240 and the receiving optical fiber 1250 respectively protrude into the cell cavity through the above-mentioned channel, and the capillary of the chromatographic separation system 1100 on the outer capillary column The column 1170 extends into the cell cavity and intersects the incoming fiber 1240 and the receiving fiber 1250, and the detection window of the capillary column 1170 is located at the intersection of the three.

The spectral response band of the CCD spectrometer 1230 is 200 nm to 900 nm, and the number of pixels is 2048 units. The CCD signal uses a serial output with a basic scan frequency of 10 桢/sec (variable) and a data bit size of 16 bits. The flat field grating monochromator structure is used to simultaneously perform time scanning and wavelength scanning detection on the absorbance of the incident light of the full measurement band when the sample passes through the detection pool. As the sample flows, the change in absorbance value of the flow component relative to time and wavelength can be detected simultaneously, becoming a two-dimensional detector that can simultaneously detect chromatographic and spectral properties.

Among them, the detection window is a quartz window, ensuring that the light transmission band is between 200nm and 900nm, thus ensuring high sensitivity measurement of the system.

The CCD spectrometer 1230 is also connected to the linkage control PC 1300. The linkage control PC 1300 adjusts the relationship between the gain of the CCD spectrometer 1230, the exposure time and the output analog voltage, and determines the sampling frequency of the CCD driving circuit to ensure the measurement accuracy.

Specifically, the nano-upup detection pool 1210 includes a metal base 1211 and an upper buckle cover 1212. The middle portion of the metal base 1211 has a pool slot 1213. The four channels are located on the metal base 1211. The entrance of the channel has a Peek nut 1214 fixed to the fiber 1240, the receiving fiber 1250 and the capillary column 1170. The four corners of the upper cover 1212 are fixed to the metal base 1211 by the M4 hexagon socket head screw 1215, and the upper cover 1212 The pool chamber 1213 is formed to surround the pool.

In order to observe the position of the detection window of the capillary column 1170 and the introduction fiber 1240 and the receiving fiber 1250 during assembly to ensure alignment of the three, the middle portion of the upper cover 1212 has a viewing port 1212a, and the viewing port 1212a is provided with a M4 slot. The flat end set screw 1212b, when it is determined that all the components are firmly connected, tighten the M4 slotted flat end set screw 1212b to avoid stray light interference.

The tank 1213 has a rubber mat 1216 covering the lead-in fiber 1240 and the receiving fiber 1250, and protects the lead-in fiber 1240 and the receiving fiber 1250.

The optical signal from the detecting light source 1220 enters the nano-upgrade detection cell 1210 through the introduction fiber 1240. In the detection cell 1210, the spectral signal is weakened by the absorption of the characteristic band by the sample, and the transmitted optical signal is then introduced into the CCD spectrometer 1230 by the receiving fiber 1250. The generated digital signal is introduced into the linkage control PC 1300 for the next data processing analysis.

Wherein, the detecting light source 1220 is a xenon lamp, and the radiation band is 180 nm-400 nm, and the integrated shutter can realize fast and stable output of the spectrum. To meet the baseline and drift requirements of the detection system in terms of temperature stability and time stability, a constant current and constant voltage two-time adjustment method is used to stabilize the output, so that the light source stability is less than 0.05%/h. Of course, it can also be other light sources.

The working process of the present invention is as follows:

The mobile phase solvent is pumped from the solvent bottle 1199 through the high pressure pump 1110 into the microfluidic mixing valve 1120, and the gradient mixing of the binary solvent can be realized. The sample sucked by the automatic sampler 1130 is pushed into the quantitative injection valve 1140, and the solvent and the sample are pumped by the high pressure pump 1110. Pumped in the form of constant current, driven in the form of constant pressure at the four-way diverter valve 1150, through the four-way diverter valve 1150 and the back pressure valve 1160 to achieve pressure-driven internal solvent and sample into the capillary column 1170, limited The function of the flow valve 1190 is to maintain a certain pressure at the outlet end of the capillary column 1170, thereby suppressing the formation of bubbles caused by sudden changes in pressure, and ensuring the stability of the system. The high-voltage power source 1198 increases the electroosmotic flow on the basis of the pressure flow. One end electrode is connected with the four-way diverter valve 1150, and one end electrode is inserted into the buffer bottle 1180 to realize simultaneous pressure and electric field separation of the solvent and the sample in the capillary column 10. Dynamically and quickly separated, the xenon lamp is irradiated onto the separated sample by introducing the optical fiber 1240 into the nano-upgrading detection cell 1210. The sample is weakened by the absorption of the characteristic band, and the transmitted optical signal is then introduced into the CCD spectrometer 1230 by the receiving optical fiber 1250. The digital signal is introduced into the linkage control PC1300 for the next step of data processing and analysis, and the entire automatic control of the ultraviolet capillary column chromatography system 1100 and the CCD chromatography spectrum detector 1200 is realized, and the micro-microflow CCD ultraviolet detection chromatogram is obtained.

Take the detection of polycyclic aromatic hydrocarbons as an example:

Experimental condition

Test sample: naphthalene, anthracene;

Sample concentration: 1 × 10 -5 g / ml;

Capillary column model: EP-100-20/45-3-C18;

Mobile phase: acetonitrile: water = 70:30;

Mobile phase flow rate: 0.08 ml / min (split ratio 100: 1);

High voltage power supply: -15KV;

Column flow rate: 800 nL / min;

Pump pressure: 15.4MPa;

Injection volume: 15nL;

Detection wavelength: 220 nm, 251 nm dual wavelength simultaneous detection.

Figure 4 is a spectrum diagram of a xenon lamp. It can be seen that the emitted light has a wavelength range of generally 190-400 nm, and has characteristic lines at 486.0 nm and 583.0 nm, which can produce a strong and stable 215-300 nm. Spectral output.

Figure 5 is a chromatogram of the separation of naphthalene and anthracene. It can be seen that the two have achieved good separation within 6 min, and the peak shape of the sample is very good, the peak has no tailing and stretching, and the symmetry is good. The peak at 3.34min is naphthalene, the peak height is 61.16mAu (220nm), the peak area is 44.5%, the peak at 5.24min is 蒽, the peak height is 100.05mAu (to 251nm), and the peak area is 48.6%. This experiment uses multi-wavelength simultaneous monitoring, which can detect the most suitable wavelengths of naphthalene and anthracene, which improves the sensitivity of detection and reduces the detection limit.

Figure 6 is a three-dimensional full-wavelength scan of naphthalene and anthracene. The abscissa axis (X-axis) is the chromatographic retention time, the ordinate axis (Y-axis) is the full wavelength of the spectrum (this experiment is set to 200-300 nm), and the Z-axis is Absorbed light intensity (mAu). Two sample peaks at 3.34 min and 5.24 min can also be seen in the three-dimensional map, and it can be seen that the maximum absorption wavelength of naphthalene is 220 nm, and the maximum absorption wavelength of rhodium is 251 nm. Two-dimensional detection and analysis of wavelength segments of interest can be performed through a three-dimensional full-wavelength spectrum.

However, it should be understood by those skilled in the art that the above embodiments are only used to illustrate the invention, and are not intended to limit the invention, as long as it is within the spirit of the invention. Variations and modifications of the examples are intended to fall within the scope of the appended claims.

Claims

A CCD-based ultraviolet capillary column detector, which comprises an ultraviolet capillary column chromatography system, a CCD chromatographic detector and a linkage control PC, the ultraviolet capillary column chromatography system and a CCD chromatography spectrum detector Connecting, the linkage control PC is connected to the ultraviolet capillary column chromatography system and the CCD chromatographic spectrum detector, and the CCD chromatographic detector comprises a nano-scale detection pool, a detection light source, a CCD spectrometer, an introduction fiber, and a receiving fiber. The nano-upgrading detection pool has a rectangular pool cavity, and the four sides of the nano-upgrading detection pool have four channels with a cross distribution and communicating with the cell cavity, and the detection light source and the CCD spectrometer respectively receive the introduction fiber and receive One end of the optical fiber is connected, and the other end of the introduction optical fiber and the receiving optical fiber respectively extend into the cell cavity through the channel, and the capillary chromatography column of the chromatographic separation system on the outer capillary column protrudes into the cell cavity and The introduction fiber and the receiving fiber cross meet, and the detection window of the capillary column is located in three At the intersection of the cross, the CCD spectrometer is also connected to the linkage control PC.
The CCD-based ultraviolet capillary column tester according to claim 1, wherein the nano-upgrade detection pool comprises a metal base and an upper buckle cover, and the middle portion of the metal base has a pool slot, the four strips The channel is located at the metal base, and the inlet of the channel has a Peek nut for fixing the introduction fiber, the receiving fiber and the capillary column, and the four corners of the upper cover are fixed to the metal base by an M4 hexagon socket head screw. And the upper buckle cover and the pool groove are combined to form the pool cavity.
The CCD-based ultraviolet capillary column tester according to claim 2, wherein the middle portion of the upper buckle cover has a viewing port, and the M4 slotted flat end set screw is disposed in the observation port.
The CCD-based ultraviolet capillary column detector according to claim 1 or 3, wherein the ultraviolet capillary column chromatography system comprises two high pressure pumps, a micro flow mixing valve, an automatic sampler, and a quantitative Injection valve, four-way diverter valve, back pressure valve, capillary column, a buffer bottle, a restrictor valve, and a high-pressure power source, wherein the two high-pressure pumps are connected to the micro-flow mixing valve, and the micro-flow mixing valve is connected to the quantitative injection valve via the automatic sampler, the four-way The four ports of the diverter valve are respectively connected to the quantitative injection valve, the positive electrode of the high voltage power supply, the back pressure valve and the inlet end of the capillary column, and the outlet end of the capillary column is connected to the restrictor valve, the buffer The liquid bottle has a buffer therein, and the restrictor valve is connected to the buffer, and a negative electrode of the high voltage power source is connected to the buffer.
The CCD-based ultraviolet capillary column tester according to claim 4, wherein the tank has a rubber pad covering the introduction fiber and the receiving fiber.
A CCD-based ultraviolet capillary column tester according to claim 5, wherein the detection light source is a xenon lamp.
A CCD-based ultraviolet capillary column tester according to claim 6, wherein the detection window is a quartz window.