ISO_NWIPs-for-Ballot

ISO/NP

Since 765 recommended to set the repetition time 766 the relaxation time T 1 is expected to be especially long for the signals used for quantification of the 767 analyte and the reference material for qNMR, it is better to perform the longitudinal relaxation time 768 measurement separately, and to set the repetition time to a value that is at least 7 times greater than 769 the relaxation time. 770 h) Number of transients: sufficient to obtain an SNR of 100 or more; 771 It is recommended to set the number of transients that enables acquisition of an adequate SNR, in 772 accordance with the target accuracy. For the SNR of a signal, the value for the signal S is defined as 773 the height of the subject signal from baseline to apex; noise N is defined as the root mean square of 774 the noise obtained from the baseline at ≥200 Hz, where there is no signal from 1 H observed in the 775 vicinity of the subject signal. To obtain the ratio, S is divided by 2 N [see ref. 11]. Since the SNR is 776 proportional to the positive square root of the number of transients, it is necessary to increase the 777 integrations by 100 times in order to increase the SNR by a factor of 10. 778 i) Dummy scan: 2 or more times; 779 j) Measurement temperature: stable, depend on sample;. 780 781 7 Measurement 782 7.1 1 H qNMR measurement condition settings 783 Set the measurement conditions suitable for quantitative analysis, in accordance with 6.9. 784 785 7.2 Measurement procedure 786 Perform the measurement operations as follows: 787 a) Place the NMR tube containing the sample solution into the NMR apparatus, and perform the 788 measurements under conditions optimized for quantitative analysis (see 6.9). 789 b) Carry out shimming before the measurements; verify that there is a good clear rise of the signals, and 790 symmetry of the signals that are the subject of the quantification. 791 792 7.3 Saving and processing FID data 793 Perform the saving and processing FID data as follows: 794 a) Adjust the phase of the signals used for quantification 795 b) Apply parameters such as the window function, zero-filling, baseline correction, integration range 796 using settings optimized for quantitative analysis. 797 the relaxation time T 1 of most organic compounds is below 7 s, even if it is long, so it is (the wait time between repeated pulses) to 60 s or longer. If

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