31results about How to "Determination does not interfere" patented technology

The invention discloses a method for measuring the content of pyridine in decitabine impurities. A methyl alcohol-N-methyl-pyrrolidone-triethylamine mixed solution is used as a solvent, and a direct injection gas chromatographic method is adopted for measurement. The problems that decitabine raw material glucoside stability is poor, dissolution is not easily achieved, the recycling rate of an existing detection method is seriously low and interference is likely to be caused by solvent peaks are solved. According to the method, it is tested that a blank solvent has no interference peaks for residual solvent pyridine measurement, the precision is good, the relative standard deviation (RSD) is only 0.46%, the reproducibility is good, the linear relation is good, the average recycling rate is high, and pyridine possibly remaining in glucoside can be accurately and quantitatively detected. Effective quality control is achieved for preparing second-class solvent pyridine in the decitabine raw material glucoside, and the quality of decitabine and drug use safety are ensured at the same time.

The invention belongs to the medical inspection field, relates to an analysis detection method of drug in the body of a person, and specifically relates to the method that the densities of fosphenytoin, phenytoin and 4'-hydroxyl phenytoin which is the main metabolite of fosphenytoin and phenytoin in can be detected at the same time. The method in the invention is characterized in that pilot sample is pretreated; fosphenytoin, phenytoin and 4'-hydroxyl phenytoin are separated with each other in an acidity flowing phase chromatographic column and are detected by UV detector. The method in the invention has the advantages of little sample, easy, swift and sensitive operation and short analysis period; furthermore, the method in the invention doesn't need expensive equipment and reagent, is suitable for clinical conventional detection and can be used to adjust the drug dose, which can guarantee safe and effective prescription and has the important clinical practice significance.

The invention relates to an analysis measurement method of internal drug, in particular to a method for quickly measuring mizonbine density of human blood plasma, which comprises adding sample into an interior label, after protein deposition pretreatment, isocratically eluting under water-type flow phase condition, separating via a chromatographic column, and detecting via an ultrasonic detector. The invention has low sample consumption, simple, quick and sensitive pretreatment, which not demands expensive device and organic solvent, with wide application, low environment pollution, low cost and the application for detecting clinical general blood drug density.

The invention provides a standard sample used for headspace analysis of trace quantity benzene in water and a method for measuring trace quantity benzene in water by using the method thereof. The method comprises the following step of dissolving a benzene solution in a polarity sulfone organic solvent with high boiling point and capable of dissolving with water and benzene to obtain the standard sample. When in use, the standard sample is diluted by water to the required concentration; wherein the mass ratio of benzene to polarity sulfone organic solvent is 1: 100-1: 1000. According to the invention, benzene concentration in the standard sample can be increased, expiry data of the standard sample is prolonged to more than 1 year; benzene sampling weight is increased, weighing error is reduced, and the weighing relative error is reduced from 10% to 1%. The invention also provides a method for measuring trace quantity benzene in water by using the standard sample, and the standard sample does not influence the benzene measurement in headspace analysis.

The invention relates to a method for determining mesalazine related substances by high performance liquid chromatography. The chromatographic conditions are as follows: the high performance liquid chromatography is adopted; octadecyl silica gel bonded silica gel is used as a filler (Gemimi C185mu m 150mm*4.6 mm); the volume ratio of a phosphate buffer to a TABH solution to a methanol to a water in a mixed solution serving as a mobile phase A is 250: 50: 260: 440; the volume ratio of a phosphate buffer to a TABH solution to methanol to water in a mixed solution serving as a mobile phase B is 250: 50: 500: 200; and gradient elution is performed, the flow rate is 1.1 ml/min, the column temperature is 35 DEG C, and the detection wavelength is 230 nm. According to the determination method of the related substances, main peaks and various impurities can be effectively separated, and the blank gradient does not interfere with the determination of the impurity H and the impurity N. Methodological verification is carried out on the determination conditions of the related substances, and the separation degree and the detection sensitivity meet the requirements.

The invention provides a method for determining the concentration of dapagliflozin in blood plasma, which comprises the following steps: pretreating a blood plasma sample, performing liquid chromatography separation on the pretreated blood plasma sample, performing mass spectrometry determination, calculating and the like. Compared with the prior art, the method has the following advantages: (1) dapagliflozin and acetate ions form charged negative ions, so the Rayleigh limit can be easily reached at the ion source, and coulomb explosion is further realized, so that the sensitivity is improved; (2) the pretreatment method is simple and convenient; (3) the specificity is high; (4) the sensitivity is high, and the lowest limit of quantitation of plasma is 1.0 ng.mL <-1 >; (5) no matrix effect exists; and (6) the method is rapid, simple and convenient to operate, accurate, high in sensitivity and low in detection limit. A basis is provided for clinical blood drug concentration determination of dapagliflozin, and the dapagliflozin is used for research, development and clinical application of new drugs. The linear range of a plasma standard curve of the method is 1.0-4000 ng.mL <-1>, and the intra-batch and inter-batch precision RSD is less than 15%.

The invention discloses a method for determination of concentration of 5, 6-dihydro-7,8-dimethyl-4,5-dioxy-4-H-pyranoquinoline-2-carboxylic acid in plasma, the method uses a liquid chromatography-mass spectrometry system for the determination, and the method is as follows: first taking a to-be-tested plasma sample, adding a certain amount of an inorganic acid for acidification, adding an organic solvent into the acidified plasma sample to precipitate proteins, centrifuging at a high speed, taking supernatant to add a certain amount of deionized water for even mixing, separating by a chromatographic column, and detecting with a mass spectrometry detector. The method is rapid, accurate, high-sensitivity, simple in operation, and suitable for the determination of the concentration of the 5, 6-dihydro-7,8-dimethyl-4,5-dioxy-4-H-pyranoquinoline-2-carboxylic acid in the plasma.

The invention discloses a method for determining concentration of licorice glycoside C2 in blood plasma. A liquid chromatography-mass spectrometry system is adopted for determination, firstly, a to-be-determined sample is taken, a certain quantity of organic solvent protein precipitation solutions are added, a chromatographic column is used for separation after pretreatment, and a mass spectrometry detector is used for detection. The method is rapid, accurate, high in sensitivity, simple and convenient to operate and suitable for determining the concentration of licorice glycoside C2 in the blood plasma.

The invention belongs to the field of medical examination and relates to a method for detecting the content of telbivudine in blood plasma by liquid chromatography-tandem mass spectrometry. Accordingto the method, without the need of blow-drying with nitrogen, a sample to be detected directly undergoes acetonitrile dilution/protein precipitation and a supernatant is taken for sample introduction,elution separation is carried out through a mobile phase in a chromatographic column, and detection is finally carried out by a tandem mass spectrometry detector. According to the method, deuterium 3-telbivudine (D3-LdT) is adopted as the internal standard, and a certain amount of acetonitrile precipitated protein is added into a blood sample. After virus inactivation in the blood plasma sample processing, telbivudine is not obviously degraded. Accuracy of the method is guaranteed, and safety of operators is enhanced. By measuring concentration of telbivudine and the internal standard throughthe tandem mass spectrometry, linearity range is within 10-10000 ng/mL, thus meeting requirements of human pharmacokinetics research. Less samples are sampled by the method, pretreatment is simple, fast and sensitive. Only universal equipment and reagents are needed. Analytical period is short, and cost is low. The method of the invention is suitable for the regulation of a hepatitis B patient treatment scheme and monitoring of routine plasma concentration.

The invention discloses a pretreatment method for detecting the content of phenolic impurities in a sample. The method comprises the following steps: weighing the sample, putting the sample into a volumetric flask, adding an acetonitrile solution of vitamin C, dissolving the sample, uniformly shaking, fixing the volume by using a formic acid solution of the vitamin C, filtering, and carrying out instrumental analysis on filtrate, wherein the content of the vitamin C in the acetonitrile solution of the vitamin C and the formic acid solution of the vitamin C is 90-110 [mu]g/ml. By adopting the pretreatment method disclosed by the invention, extremely low detection limit and quantitation limit can be achieved in phenol impurity detection, and the repeatability is good; the stabilizing time of the reference substance solution can be prolonged to 30 hours, the stabilizing time of the standard recovery solution can be prolonged to 11 hours, meanwhile, the vitamin C and the phenol target object can be effectively separated in a corresponding chromatographic system, and the determination of the target compound is not interfered.

The invention provides a method for determining the concentration of nilotinib in blood plasma. The method comprises the following steps: pretreating a blood plasma sample, and carrying out liquid chromatography separation, mass spectrometry determination, calculation and the like on the pretreated blood plasma sample. Compared with the prior art, the method has the following advantages: (1) the pretreatment method is simple and convenient; (2) the specificity is high; (3) the sensitivity is high: the lowest quantification limit of plasma is 2.5 ng.mL<-1>; (4) isotope internal standard: no matrix effect exists; and (5) the method is rapid, simple, convenient and accurate to operate, high in sensitivity and low in detection limit. A basis is provided for clinical blood drug concentration determination of nilotinib, and the method serves research, development and clinical application of new drugs. According to the method, the linear range of a plasma standard curve is 2.5-2000 ng.mL<-1>,and the within-run precision RSD and between-run precision RSD are both smaller than 15%.