44 results about "Iodometry" patented technology

Provided is a method for measuring copper content in tin-silver-copper solder through iodometry. The method comprises the following steps: a copper standard solution is prepared and the titer of the copper standard solution is measured. A sample to be measured is weighed and added into an Erlenmeyer flask. Concentrated sulfuric acid is added and the mixture is heated for dissolution. The above solution is cooled to the room temperature, perchloric acid is added, after the sample is dissolved fully, heating is carried out until white smoke is generated, concentrated hydrochloric acid is dropwise added into the above solution in batches to remove the tin element in the solution, and the solution is subjected to concentration. The Erlenmeyer flask is taken down and cooled to the room temperature, deionized water is added, the constant volume is 100mL and the above solution is shaken up. Then an ammonium hydroxide solution is added and copper ammonia complex ions are formed. Then ammonium bifluoride is added into the solution and stirred until the blue color disappears. The above solution is cooled to the room temperature by utilization of running water. The solution is placed for half a minute, then potassium iodide is added, and immediately the solution is subjected to titration by a sodium hyposulfite standard solution until a shallow yellow color appears. Then a potassium thiocyanate solution and a starch solution are added, and the solution is subjected to titration by the sodium hyposulfite standard solution until a blue color disappears. The volume of the consumed sodium hyposulfite solution is recorded, and the content of copper in the sample is calculated.

The invention belongs to the field of food detection, and particularly relates to a method for preparing an enzyme electrode and rapidly detecting the peroxide value of vegetable oil. The method comprises the steps of: selecting a glassy carbon electrode for use; firstly preparing a Nafion-methylene blue membrane electrode, then adopting a bovine serum albumin-glutaraldehyde crosslinking method to fix horse radish peroxidase (HRP), and obtaining a final HRP electrode; and then using the HRP electrode to rapidly detect the peroxide value of the vegetable oil. The method is high in sensitivity, good in selectivity, high in accuracy, short in response time, less in interference and superior to the traditional iodometry, thus being a simple, rapid, convenient and easy method for measuring the peroxide value and having the potential of realizing automatic on-site measurement.

The invention belongs to the field of analytical chemistry, and particularly discloses indirect iodometry dynamics spectrophotometry for measuring vitamin C. The spectrophotometry specifically comprises steps as follows: at the room temperature, using a cuvette of 1 cm as a reaction container, adding 0.50-1.40 mL of a 200 mu g / mL vitamin C standard solution and 1.60-2.50 mL of a 0.5% starch solution to enable the volume of the mixed solution to be 3.00 mL, adding 0.20 mL of a 0.200 mg / mL potassium iodate solution and 0.10 mL of a 0.15 mol / L of sulfuric acid solution, evenly shaking the mixture, quickly placing the mixture into a reagent blank for a photometer, performing dynamics spectrophotometry scanning at the wavelength of 600 nm to measure the peak absorbance within a short time, wherein the peak absorbance has a good linear relation with the concentration of the vitamin C. The spectrophotometry has the advantages that the spectrophotometry is convenient, accurate, micro and quick, used drugs are low in cost, easy to obtain, non-toxic, pollution-free and environment-friendly and the like, and is used for measuring the vitamin C in biological samples, drug samples and the like.

The invention relates to a method for measuring the copper content in high-lead-gold concentrates, and belongs to a method for measuring the copper content in ores. According to the method, a nitric acid-potassium chlorate saturated solution is used for dissolving a test specimen; sulfuric acid is used for precipitating lead ions; after the filtering, filter liquid is distilled until sulfuric acidsmoke thoroughly disappears; materials with the copper content being less than 2 percent are leached by hydrochloric acid; AAS determination is performed; the materials with the copper content beinggreater than 2 percent are leached by distilled water; the iodometry titration determination is performed. The copper content determination range in the lead concretes is 0.050 to 25.00 percent; the determination accuracy is improved; the copper measurement stability of the high-lead gold concentrates is improved; the measurement range is expanded; good application performance is realized.

The invention relates to a method for measuring the total sugar content of a chlortetracycline fermentation broth with a refractometer, and the method is characterized by accurate measuring result and low cost. The method comprises the steps of: (1) collecting original data: measuring the sugar content data of a standard sample by iodimetry, with the sugar content of the sample at a gradient concentration of 0-17%; (2) inputting the data measured in step (1) into the refractometer; (3) dropping the sample with sugar content of 0-17% for measuring directly in a determination analysis pool so as to conduct measuring. The method of the invention has the advantages of accurate measuring result and fast detection speed. Meanwhile, after one time of standard data input, no input and detection through iodometry are needed once again during sugar content detection of the sample at a later stage, so that a lot of reagents can be saved. The method of iodometry is complicated for operation, while the adoption of a refractometer is simple in operation. The employment of a refractometer for detection reduces the labor intensity of technicists and improves the working efficiency.

The invention provides an oxygen consumption rate and choke point measuring device of fishes, and relates to a device for measuring oxygen consumption rate and choke point of the fishes. The invention aims to solve the problems that a special device for measuring the choke point of the fishes is lacked, and the existing oxygen consumption rate and choke point of the fishes cannot be measured in the same device by an iodometry method. A respiratory chamber of the device is of a cylinder structure; a cover plate is arranged at an opening end of the respiratory chamber; a water outlet pipe is arranged on the cover plate; a water outlet valve is formed on the water outlet pipe; an axis, vertical to the cylinder, of a pushing plate is arranged in the respiratory chamber; screw threads are formed at the external surface of a water inlet pipe; one end of the water inlet pipe is fixedly connected with the pushing plate, and the other end of the water inlet pipe is in threaded connection with a nut after penetrating through a closed end of the respiratory chamber; the nuts are in embedded connection with the external wall of the respiratory chamber; a water inlet communicated with the water inlet pipe is formed in the pushing plate; a water inlet valve is formed on the water inlet pipe; one end of a round bar is fixedly connected with the pushing plate, and the other end of the round bar penetrates through the closed end of the respiratory chamber. The device is used for measuring the oxygen consumption rate and choke point of the fishes.

The invention relates to a method for measuring the total sugar content of a chlortetracycline fermentation broth with a refractometer, and the method is characterized by accurate measuring result and low cost. The method comprises the steps of: (1) collecting original data: measuring the sugar content data of a standard sample by iodimetry, with the sugar content of the sample at a gradient concentration of 0-17%; (2) inputting the data measured in step (1) into the refractometer; (3) dropping the sample with sugar content of 0-17% for measuring directly in a determination analysis pool so as to conduct measuring. The method of the invention has the advantages of accurate measuring result and fast detection speed. Meanwhile, after one time of standard data input, no input and detection through iodometry are needed once again during sugar content detection of the sample at a later stage, so that a lot of reagents can be saved. The method of iodometry is complicated for operation, while the adoption of a refractometer is simple in operation. The employment of a refractometer for detection reduces the labor intensity of technicists and improves the working efficiency.

The invention discloses a method for improving iodometry measurement accuracy of samples containing interfering substances. According to the method, a proper amount of nonionic surfactant is added on the basis of a conventional iodometry, and the problems that certain samples containing the interfering substances become turbid in the titration testing process and even accurate measurement is difficult due to iodine precipitation are successfully solved. By means of the method, a titration reaction is quick and sufficient, a titration end point is clear and transparent, the end point is accurately judged through color changes of iodine even if starch can not normally display colors, and a test result is good in precision and accuracy. Reagents used in the method are all conventional, safe, free of harm, easy to operate and suitable for being popularized in detection organizations and research institutions.