493results about How to "High analytical sensitivity" patented technology

An electrochemical microfluidic device has one or a plurality of microstructures, such as a microchannel, in which an electrically conductive means is integrated to reduce the ohmic resistance within the microstructure and hence to improve electrochemical measurements particularly when large current densities are involved. The electrically conductive means can be connected as a counter-electrode and can be used to re-generate the product of the reaction occurring at the working electrode. A method of fabricating electrochemical microfluidic devices comprising such an electrically conductive means is also disclosed. The invention may particularly be used in all electrochemical sensor applications where detection is performed in small volumes.

An ion source able to ionize both liquid and gaseous effluents from interfaced liquid or gaseous separation techniques. The liquid effluents are ionized by electrospray ionization, photoionization or atmospheric pressure chemical ionization and the gaseous effluents from sources such as a gas chromatograph are ionized by a corona or Townsend electrical discharge or photoionization. The source has the ability to ionize compounds from both liquid and gaseous sources, which facilitates ionization of volatile compounds separated by gas chromatography, low volatility compounds separated by liquid chromatography, as well as highly non-volatile compounds infused by electrospray or separated by liquid chromatography or capillary electrophoresis.

The present invention refers to the detection of EGFR mutations in a blood (serum/plasma) sample from a subject. The method comprises: (i) obtaining the DNA from said sample; (ii) amplifying the nucleic acid sequence corresponding to a specific region of the EGFR gene by means of PCR using a Protein-Nucleic Acid probe; 10 and (iii) detecting said mutation.

The present invention provides a mass spectrometer having an ion lens capable of transporting an ion having a large mass to charge ratio with a high level of ion-passing efficiency even under a low-vacuum atmosphere. In conventional atmospheric pressure ionization mass spectrometers or similar mass spectrometers, applying an excessively high voltage to the ion lens undesirably causes an electric discharge. Therefore, the passing efficiency for an ion having a large mass to charge ratio cannot be adequately improved, which leads to a poor detection sensitivity. To solve this problem, the mass spectrometer according to the present invention includes a voltage controller 21 that controls a variable radiofrequency (RF) voltage generator 24 so that both the amplitude and the frequency of the RF voltage applied to the lens electrodes of an ion lens 5 are changed according to the mass to charge ratio of an ion to be analyzed. This control enables the ion lens 5 to focus an ion and transport it to the subsequent stage with a high level of passing efficiency even in the case of analyzing an ion having a large mass to charge ratio. Thus, the detection sensitivity is improved. The aforementioned control is conducted on the basis of the control data stored in a voltage control data storage 22. These data are obtained in advance by a measurement of a sample containing a substance having a known mass to charge ratio, in which the intensity of the signal of an ion detector is maintained while the analysis conditions are changed.

The invention relates to a method for measuring alkaloid in tobacco and tobacco products, which is characterized by dissociating alkaloid from the tobacco and tobacco products by using sodium hydroxide solution, extracting the alkaloid from samples by using triethylamine/trichloromethane solution, and detecting content of five kinds of alkaloid with GC-MS ( Gas Chromatograph-Mass Spectrum) quantitative analysis. Compared with other methods for analyzing the alkaloid, the invention has the advantages that alkaloid is separated from the tobacco by DB-35MS chromatographic columns so as to separate nornicotine and myosmine in the tobacco and accurately quantify target matters; batch sampling is carried out on the separation of nicotinamide and other alkaloid so as to detect the nicotinamide with high content in the tobacco and meet the quantitative analysis of other alkaloid with low content; the standard working curves of standard matters are separately compounded so as to avoid influence on quantization of other alkaloid by alkaloid catabolite existing in the standard samples. The method is simple and convenient and has the advantages of good repeatability, high analyzing and measuring sensitivity, and accurate quantization.

An exhaust line (15) connected to a chamber (13) comprises a TMP (22) and a dry pump (23). The chamber (13) and the TMP (22) are connected by a first exhaust pipe (25), and the TMP (22) and the dry pump (23) are connected by a second exhaust pipe (28). A measuring section (24) monitors a partial pressure of TiCl₄ or NH₃ in an exhaust gas flowing in the second exhaust pipe (28). Two types of process gases are alternately supplied into the chamber (13) for a predetermined time, and when the partial pressure of one of the supplied process gases in the exhaust gas is reduced to a predetermined value, a control means (12) starts supplying the other process gas.

An ion mobility spectrometer (IMS) for the detection of trace gaseous molecular compounds dissolved or suspended in a carrier gas, particularly in ambient air, without preconcentration or the trapping of analyte particles. The IMS of the invention comprises an ionization volume of greater than 5 cm³ and preferably greater than 100 cm³. The larger size ionizers of this invention enable analysis of trace (<1 ppb) of sample compounds in the gas phase. To facilitate efficient ion motion through the large volume ionization and reaction regions of the IMS, an electric field gradient can be provided in the ionization region or in both the ionization and reaction regions. The systems can be implemented with radioactive ionization sources, corona discharge ion sources or ions can be formed by photoionization. In specific embodiments, particularly when the sample gas is ambient air, the sample gas is heater prior to entry into the instrument, the instrument is run at temperatures above ambient, and the instrument can be heated by contact with heated sample gas exiting the instrument.

An ion source able to ionize both liquid and gaseous vapors from interfaced liquid separation techniques and a solids/liquid atmospheric pressure (AP) probe. The liquid effluents are ionized by electrospray ionization, photoionization or atmospheric pressure chemical ionization and the vapors released from a probe device placed in a heated gas stream in the AP source are ionized by a corona or Townsend electrical discharge or photoionization. The source has the ability to ionize compounds from both liquid and solid sources, which facilitates ionization of volatile and semivolatile compounds by applying heat from a gas stream as well as highly non-volatile compounds infused by electrospray or separated by liquid chromatography or capillary electrophoresis.

The invention provides a homogeneous phase immunoassay POCT detection technique and a system using same. The homogeneous phase immunoassay POCT detection technique has the characteristics of high sensitivity, high precision and wide range of chemiluminescence immune assay technique and rapidness, portability and the like of a POCT detection technique; in addition, as pure liquid phase detection, the homogeneous phase immunoassay POCT detection technique overcomes the problem that CV is relatively high due to an NC membrane, so that the detection precision is high, generally the CV can be controlled to be within 5%, and the level of precision of the POCT detection technique can reach or even exceed that of the chemiluminescence immune assay technique. In the system using the homogeneous phase immunoassay POCT detection technique, a reagent card and a POCT analyzer are separately designed, a sample to be tested is acquired by using the reagent card, and the system is convenient to carry over.

The invention discloses a common rapid detection method for various pesticide residues in soybeans. The common rapid detection method is characterized by particularly comprising the following steps: homogenizing and extracting a soybean sample by acetonitrile; carrying out salting-out and centrifuging to obtain a supernatant; purifying by using a solid phase extraction column to obtain a sampling solution; preparing a mixed standard solution and preparing a base material adding standard curve; simultaneously detecting 306 types of pesticide residues in the soybeans by a gas chromatography-tandem mass spectrometer; finally, calculating the concentration. The common rapid detection method has the advantages that the effect of the base material and background interferences are reduced and the anti-interference capability of the method is improved greatly; the analysis sensitivity is improved; the detection linear range is 0-0.2microgram/milliliter; the detection is limited to be 0.01mg/kg; the recycling rate is 60%-120%; the relative standard deviation RSD is less than or equal to 20%; the recycling rate is ideal and the precision degree is good; the common rapid detection method is simple and rapid, is low in background interferences, good in selectivity and high in sensitivity.

The invention provides a system and a method for measuring the content of 57 volatile organic compounds in ambient air. The system comprises a four-way valve, a gas chromatograph and a three-stage cold trap preconcentrator; the four ports of the four-way valve are respectively connected with a pre-separation column, a first secondary separation column, a second secondary separation column and a helium gas source; and the gas chromatograph is provided with a flame ionization detector and a mass spectrometry detector. The method comprises the following steps: (1) preparing a mixed standard use gas; (2) preparing an internal standard use gas; (3) collecting an ambient air sample; (4) establishing a standard curve of a target component; and (5) taking the ambient air sample to be tested, removing interfering substances through the three-stage cold trap preconcentrator, performing gas chromatography-mass spectrometry analysis in the mass spectrometry detector after focusing is performed, obtaining the content of each component according to a peak area and the standard curve established in the step (4), and calculating the concentration of the sample to be tested according to a sample injection volume of the sample to be tested. By adopting the method provided by the invention, the simultaneous analysis of two detectors is achieved by once sample injection, thereby avoiding the influence of the interfering substances on the measurement result simply and effectively.

The invention belongs to the technical field of organic photoelectric functional material, and specifically provides a preparation method of an aza BODIPY based near infrared fluorescent dye and application of the near infrared fluorescent dye to Hg<2+> detection, cell imaging and biomarker. The material is a micromolecular near infrared dye based on aza BODIPY, and near infrared absorption and emission wavelength of which are adjusted by changing Ar group. The material has a structural general formula shown as below, simple synthesis steps with mild conditions, can be used as a near infrared fluorescent material and has good application prospect in ion detection, cell imaging and biomarker.

A device is used to measure contamination directly in transport enclosures of FOUP or SMIF type, for example. The transport enclosure is placed on an adapter that sets up direct communication between it and an external gas analyzer. The gas analyzer ionizes the sampled gases and performs the analysis by measuring a parameter of the ions resulting from this ionization. This measures very low levels of gaseous contamination in real time.

The invention discloses a method for detecting alkaloids and nitrosamines in tobaccos simultaneously, and belongs to the technical field of tobacco chemical composition detection. The method comprises the working procedures of: sample extraction, purification, analysis and quantification. Firstly an internal standard solution and ultrapure water are added into tobacco leaf powder, extract liquor passes through a filter film after ultrasonic extraction, then methanol is added, protein is removed through centrifugation after shaking, and supernatant is subjected to liquid chromatography-mass spectrometry. After standard solutions of compounds to be detected with different concentration gradients are prepared by adopting a mixing preparation method, and the liquid chromatography-mass spectrometry is carried out, standard curves of instrument responses of the compounds to the actual concentrations of the solutions are drawn, curve equations are fitted, and the detection concentrations are calculated according to measured values of the instrument responses of the compounds to be detected and converted to the actual concentrations of the compounds to be detected in tobacco samples. The detection method provided by the invention can be used for carrying out the qualitative and quantitative analysis on alkaloids and nitrosamines in the tobacco samples simultaneously, and is easy and convenient to operate, good in reproducibility, high in analytic sensitivity and accurate in quantification.

The invention discloses a double channel resonance enhancement laser induction penetrate spectrum trace element analyzer, which includes the laser, the monochromator, the photo detector, the oscilloscope and the computer, the states laser through the beam-splitting piece BS connects the sample channel and the photo source channel light signal; there is lens L1, the resonance photo source, coupling lens assembly L3 and L4 in turn installs on the photo source channel; there is reflector RM1, lens L2 in turn on the sample channel; the sample channel and photo source channel connect with the sample light signal, the sample through the light gather system connects the monochromator light signal, the monochromator connects the photo detector, the photo detector connects the oscillograph, the oscillograph connects the computer. The invention also discloses an analysis method of the double channel resonance enhancement laser induction penetrate spectrum trace element analyzer. The analyzer has simple structure and low cost, greatly enhanced the analysis sensitivity and reduced the examination limit.

The invention relates to a determination method of aroma components in an electronic cigarette aerosol, and belongs to the technical field of assay determination. According to the method, a Cambridge filter is used for collecting grain phase compositions in the electronic cigarette aerosol, absorption bottles collect gas phase compositions in the electronic cigarette aerosol in cold trap conditions, then ultrasonic extraction is carried out by using dichloromethane, and deionized water is combined to carry out liquid-liquid back-extraction, the interference of large amounts of alcohol in the aerosol is eliminated, finally, the gas chromatography mass spectrometry is combined to perform qualitative and quantitative analysis. With the adoption of the determination method of the aroma components in the electronic cigarette aerosol disclosed by the invention, loss or decomposition of volatile aroma components in the electronic cigarette aerosol can be effectively avoided, multiple volatile aroma components can be simultaneously analyzed, the repeatability is better, the sensitivity is high and the operation is simple, and the interference of matrix components and solvents can be avoided, so that the determination method of the aroma components in the electronic cigarette aerosol has certain advantages in detection of the volatile aroma components in the electronic cigarette aerosol.

The invention provides a detection method for simultaneously determining a plurality of flavor substances in cigarette cut tobaccos. The flavor substances comprise furanone, isoamyl isovalerate, maltol, tabanone, menthol, ethyl maltol, 5-hydroxymethyl furfural and anethole. The method utilizes a solvent oscillation extraction method and a gas chromatography and mass spectrometry method to simultaneously determine the contents of a plurality of the flavor substances in the cigarette cut tobaccos; and the contents of a plurality of the flavor substances in a detection sample is calculated by the steps of preparing the detection sample, preparing a standard solution of a plurality of the flavor substances, preparing a sample solution and carrying out gas chromatography and mass spectrometry analysis. The method disclosed by the invention can accurately measure the contents of a plurality of the important flavor substances in a cigarette cut tobacco sample and is used for effectively evaluating the flavoring uniformity of the cigarette cut tobaccos, so as to provide the powerful technical support to a cigarette tobacco primary process. The method disclosed by the invention has the advantages of rapidness and convenience, simplicity in operation, good repeatability and high assay determination flexibility; and the recycling rate of a plurality of the important flavor substances can meet the requirements.

In an ion trap mass spectrometer including an ion trap space surrounded by a ring electrode and two end cap electrodes placed opposite each other with the ring electrode between them, a method of trapping object ions of a predetermined mass-to-charge ratio in the ion trap space more assuredly and effectively. The method includes the steps of: applying an RF voltage to the ring electrode to trap the object ions; and applying an auxiliary AC voltage to the end cap electrodes, where the auxiliary voltage has a frequency spectrum with a first notch at the basic frequency of the object ions and a second notch at a a beat frequency. Then the second stage is performed where another auxiliary AC voltage of the beat frequency is applied to the end cap electrodes to expel non-object ions still remaining in the ion trap space.

The present invention provides a novel method for diagnosing, monitoring, prognosing and staging Lymph Node (LN) status in colorectal cancer (CRC) that is more sensitive and accurate than conventional detection technologies such as histopathology. The Guanylyl Cyclase C (GCC) gene is specifically expressed in apical epithelial cells of the GI tract from the duodenum to the rectum and the detection of GCC mRNA in LNs is indicative of the presence of metastases. Quantitative RT-PCR (RT-qPCR) detection of GCC mRNA to identify the presence of colorectal cancer (CRC) cells in LNs has the potential to aid in CRC staging. When used in combination with glucuronidase B (GUSB), accurate quantification of GCC can be achieved with less than a 2-fold variation between intact and highly degraded RNA specimens. The invention also relates to a newly designed GCC/GUSB assay that uses relative quantification having improved prognostic value for time to recurrence and relapse-free survival in Stage I or II colon cancer patients. The GCC/GUSB assay also improves the statistical power of prognosis stratification for relative risk of recurrence and relapse-free survival.

The invention relates to a method for measuring volatile fragrance components of an electronic cigarette. The method comprises the steps of adding electronic cigarette liquid into a headspace sample injection bottle, adding a solvent into the headspace sample injection bottle for uniform mixing, and sealing a bottleneck of the headspace sample injection bottle through a bottle cover; performing aging treatment on a solid-phase microextraction needle fiber head at a gas chromatography sample injection opening; performing headspace solid-phase microextratcion on the electronic cigarette liquid; performing desorption on substances obtained by extraction at the gas chromatography sample injection opening; qualitatively and quantitatively analyzing the desorbed substances through a gas chromatography-mass spectrometer. According to the method, the loss or the decomposition of the volatile fragrance components of the electronic cigarette can be effectively avoided; multiple volatile fragrance components can be simultaneously analyzed; the method is high in repetitiveness, high in sensitivity and easy to operate; the interference caused by base body components and the solvent can be avoided; the method has a certain advantage in detecting the volatile fragrance components.

The invention relates to a method for simultaneous analysis of plastic additives, monomers and estrogen metabolites in urea, specifically to a method for rapid analysis of phthalate metabolites, bisphenol A and estrogen in urine, belonging to the field of analytical chemistry. According to the method, after chromatographic separation of PAEs, phenolic compounds and estrogen metabolites in urea under acidic conditions, a solution with a pH value is injected into a mobile phase flowing out from a chromatographic column, so the mobile phase is adjusted an alkaline mobile phase before entering mass spectrometry; and thus, the ionizationoun efficiency of a to-be-detected substance in a mass spectrometric ion source is improved, phthalate metabolites, bisphenol A and estrogen in urine are analyzed at the same time in one sample introduction, and analysis efficacy is enhanced.