A:Generally, the shelf life of liquid reagents is 3-6 months, preferably in the refrigerator; some reagents are ready for use.
A:Use distilled water and related liquid reagents according to the requirements of the instructions
A:The blank test is a test carried out in the same steps and conditions as the test sample without adding a sample. The test result is called a blank value; the value obtained when the sample is analyzed is subtracted from the blank test value. It is the final analysis result.Blank test is an important part of laboratory quality control, and its accuracy is crucial to improve the accuracy of test results.The blank test value reflects the combined effects of the noise of the test instrument, the impurities in the reagent, the environment and the contamination during the operation on the determination of the sample, which is directly related to the accuracy of the most comprehensive result of the measurement.
A:Follow the instructions in the manual
A:If there is no display or flower screen, no display may cause the potentiometer to be misplaced during the transportation process. It is necessary to disassemble the instrument and re-adjust it with a screwdriver. It may also be damaged or the cable is aging. The flower screen is usually not initialized and waits. Initialization is complete.
A:Generally, the digestion button is pressed in advance, or the time setting is incorrect.
A:When possible, the fuse is burned out, the fuse is replaced, and the flashing (indicator) during heating is normal control during the stabilization process.
A:When the blank test value is too high, the test water, reagents, gauges and containers should be thoroughly inspected, the performance of the measuring instrument and the state of the test environment should be thoroughly checked to minimize the blank test value.
A:1. Determine the applicable double dilution of distilled water, including magazines that affect the results of the experiment, such as distilled water containing ammonia.2. Glassware such as pipettes and colorimetric tubes are not thoroughly cleaned, and these factors have a great influence on the experimental results.3. The quality of the ammonia-free water used in the experiment is not good, and the ammonia content is relatively high, which leads to the high blank value obtained by the experiment, which is the most important reason.4. The reagent is contaminated and the resulting blank paper is too high.
A:Washing of glassware: The glassware used should be cleaned with about 20% dilute sulfuric acid and then rinsed with ammonia-free water for several times. Otherwise, the blank paper may be too high or the parallelism may be poor.Reagent selection: In the process of alkaline potassium persulfate (or potassium perchlorate) digestion spectrophotometric determination of total nitrogen, reagents are essential. First, the purity of the reagent is related to the height of the blank paper and the accuracy of the measurement results. The total nitrogen content of the analytically pure reagent does not exceed 0.005%, but due to the difference in the quality of the reagents, the nitrogen content of some manufacturers and batches of reagents often fails to meet the requirements, resulting in a high blank.Selection of experimental water: If the blank of the experiment is not ideal, the test water and reagents need to be tested to select the water with the lowest nitrogen content to obtain the ideal blank value.
A:The blank test value is higher or lower;The content of the target in the water sample is too high, has exceeded the range and color range, and the sample is diluted according to the standard color.
A:The colorimetric tube or cuvette is not cleaned.The dust inside the colorimetric tank should be cleaned up. 3. It is also possible that the gas parts are aging.