Generally, after a series of relevant data have been obtained, the following principles shall be recorded, calculated and dealt with.
        1, rules of record and operation
        The data recording and calculation in food analysis are carried out in accordance with the effective numerical calculation principle:
        ①In addition to special provisions, the general suspect number is the last one, with an error of + 1 units;
        ② When complex operations are performed, one or more of the processes may be retained, and the final result should be taken in the proper number of bits;
        ③ The result of the addition and subtraction method, the number of digits retained after the decimal point, should be the same as the number of decimal places in the number of participants;
        ④ Multiplication and division calculation results, the effective number of bits should be retained in operation and the number of digits in the effective number of the same;
        2, the suspicious value of the choice
        Repeated measurements of the same sample often reveal that the individual data is substantially different from other data, and that these undesirable data cannot be arbitrarily discarded. Unless the analysts have sufficient reason to verify that these values are excluded by some accidental error or extraneous interference, the choice of these data should be based on the error theory.
        3, standard curve drawing
       With the photometric method, some components were measured by fluorescence spectrophotometry, atomic absorption spectrophotometry, chromatography, often need to prepare a certain gradient series of standard solution, the coefficient of determination (absorbance, fluorescence intensity, peak height), standard curve. Under normal circumstances, the standard curve should be a straight line through the origin, but in the actual measurement, a one or two point often appears, deviate from the straight line then the regression method to draw standard curve by the least square, can get the most reasonable graphics. The least square method is used, and then the standard curve is plotted by regression equation.
        4. Calibration of measurement results
        In food analysis, often because of system error, the determination of the actual content of the above or below the detection object, the recovery rate is 100%, so the need for legal recovery by adding recovery at the same time samples, then the recovery rate of the determination results of sample press type corrected.

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