Under normal circumstances, how often should the curve be generated?

Under normal circumstances, it is done once a year; if your instrument malfunctions, you will need to create the curve again before conducting the testing

It depends on what kind of work curve is being used. We prepare arsenic calibration curves using photometry every half month. Decide based on your actual situation. It should be done frequently at the beginning, and the frequency can be increased slightly once stability is achieved. In case of special circumstances, such as re-calibration of the instrument or replacement of the drug batch number, the working curve should be corrected immediately.

1. If gas chromatography is used to analyze finished products upon leaving the factory, the working curve is generally calibrated once every half month. 2. If a spectrophotometer is used to detect metal impurities in inorganic products through colorimetric methods, the working curve is usually calibrated once a week or even daily. 3. When flame atomic absorption or ICP is used to detect metal ions, calibration is typically carried out daily using a standard sample, with a working curve established on a weekly basis. 4. For detecting ppb levels and metal impurities using graphite furnace atomic absorption, the frequency of calibration depends on the required accuracy of the analysis. 5. In the case of environmental testing, it is recommended to perform calibration using standard samples daily, as well as calibrating the working curve once every half month. In short, each situation requires a tailored approach

After reading the replies from everyone above, I’m speechless. Who can tell me what curve he wants? Please let the original poster clarify it themselves.

In fact, regardless of the type of standard curve, whether it needs to be redone depends not on time; if the instrument is in good condition and the reagents and methods used for analysis remain unchanged, there is no need to redo it for a year or two. In accordance with quality control requirements, when using a standard curve, it is necessary to first test it with quality control samples. If the analysis results of the newly prepared quality control samples are accurate, then the standard curve is valid and can be used without needing to be recreated. Conversely, if the analysis results of the quality control samples do not meet the required standards, even a newly prepared standard curve cannot be used, and it must be prepared again.

This view is at least not applicable to instrumental analysis. Unless you redo the curve every time before making a sample. Creating instrument curves is like a person needing to \"take a bath\". First, it is necessary to do it regularly ； Second, it is necessary to act promptly ； On this basis, whenever you create a sample, drawing curves again – whether you say it shows seriousness or carefulness – it’s always a positive thing. If it’s not based on this, it’s just last-minute cramming. Personal opinion.

Actually, what I asked about was the total phosphorus curve. Recently I conducted operation tests on the operators, using total phosphorus standard samples for comparison, but the differences were huge – 0.6 mg/l was measured as 1.22 mg/l.

It depends on how often you use it; if you use it every day, it should be calibrated at least once a month

You still need to calibrate it daily with standard samples

Are everyone upstairs working so hard on their curves? Based on experience, I usually prepare working curves for mature spectrophotometry methods only once or twice a year.

We do it every six months; sometimes it’s once a year as well

We also do it roughly once a year; only when a newly installed instrument is used, or when obvious errors in the data are detected during the analysis, do we redo the curves.

Generally, when there aren’t many analysis tasks to carry out, I use the samples that are still available – those products have already been sold for RMB or $ – and I perform a GC analysis; if the results fall within the acceptable error range, I consider the instrument to be in good condition and don’t feel the need to create a calibration curve. For other projects, I also often use this method for comparison. Am I being too lazy by doing this?:loveliness: ?