ISO_NP_24583_Form04

ISO/NP

Furthermore, for the confirmation of validity, it is also quite useful to measure the same sample using a 912 different analytical method and compare the results. In addition, participation in appropriate inter- 913 facility comparisons and verification of analysis values with appropriate CRMs is also recommended as 914 a highly objective means of ensuring the reliability of the analysis values [see ref. 10, 20 and 21]. 915 Uncertainty should be estimated considering the factors described in the below and caluculated using a 916 coverage factor that ensures a confidence level of at least 95 % (usually: k =2) [see ref. 22]. 917 An example of the possible uncertainty factors for qNMR is shown below: 918 uncertainty of balance; 919 uncertainty from weighing of sample and CRM; 920 uncertainty of CRM used; 921 variation of measurements, if necessary, perform the buoyancy correction. measurement; 922 uncertainty of molar mass of analyte and CRM; 923 uncertainty of number of 1 H contributing to the signals of analyte and CRM; 924 uncertainty of NMR apparatus. 925 926 NOTE Depending on the applied balance calibration procedure, the calibration results might already contain 927 information on the so-called uncertainty in use, i.e. the uncertainty when weighing a sample of a certain mass; in 928 this case, the balance uncertainty is already included in the uncertainty in use and does not have to be considered 929 separately [see ref. 9]. 930 931 932 933 934 10 Test report 935 The test report shall contain at least the following information: 936 a) Date of the sample preparation and of measurement; 937 b) Identification of the sample, reference material for qNMR and deuterated solvent used (type of 938 reference material and deuterated solvent, purity, lot number, etc.); 939 c) Measurement conditions, repeatability of measurements, and conditions of data acquisition; 940 d) Results; 941 e) Attribution information of signals; 942 f) Other details, as required. 943

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