ISO_NWIPs-for-Ballot

ISO/NP

k is the constant related to the measurement of the sample solution being analysed; 427 N a is the number of protons in the analyte; 428 N s is the number of protons in the reference material for qNMR; 429 c a is the molar concentration of the analyte; 430 c s is the molar concentration of reference material for qNMR; 431 M a is the molar mass of the analyte; 432 M s is the molar mass of the reference material for qNMR; 433 m a is the mass of the analyte compound; 434 m s is the mass of the reference material for qNMR. 435 Although there are some conditions that must be met, such as no interaction (such as reactions) 436 between the molecules in the solution, and the existence of separated signals with different chemical 437 shifts, Formula (4) indicates that it is possible to measure the content or purity of the analyte compound 438 by performing 1 H qNMR measurements under conditions ensuring quantitative performance if there is 439 a reference material for qNMR with a known purity. In other words, if a material with an accurate purity 440 is provided as a reference, if we have a reference material for qNMR with a known molar mass , it is 441 possible to determine the content or purity of other analyte substances within the same solution 442 measured at the same time. Specifically, if the purity value assigned to the reference material for qNMR 443 has been established in a manner traceable to the SI and the procedure used for the implementation of 444 the qNMR method has been appropriately validated, the method can be used to establish the SI- 445 traceability of the result for the content or purity of the analyte 446 The six key procedures for obtaining precise analysis results with 1 H qNMR are: 447 - Precisely weigh the sample and calibrant materials 448 - Ensure the analyte contained in the sample and calibrant dissolve completely. 449 - Acquire the data under conditions that are suitable for quantification 450 - Select a signal for quantification that does not include impurity signals[see ref. 14] 451 - Process the spectrum properly, phase and baseline correct 452 - Integrate sample and reference peaks correctly 453 NOTE If a signal for quantification is overlapped to impurities, some evaluation methods such as line fitting is 454 effective for eliminating the impurities from signals [see ref. 17]. 455 5 Apparatus and equipment 456 5.1 General 457 The applicable nuclear magnetic resonance apparatus (NMR apparatus) is the type that uses a pulse 458 Fourier transforms (FT) method. 459

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