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Table 4 Confidence interval of the titration value based on the nitrogen content, according to examples of uncertainty of measurements of each individual assay––Mat-CHN recalculations

From: Mat-CHN software for drug substance titrations in discovery and development

Experimental determination Value (%w/w) Uncertainty of measurement (examples) Lower value (%w/w) Higher value (%w/w) Lower mole number recalculated Higher mole number recalculated
Water 0.80 5% (relative) 0.76 0.84 0.2540 0.2820
Water 0.85 5% (relative) 0.81 0.89
Butanol-1 0.35 5% (relative) 0.3325 0.3675 0.0262 0.0292
Des-Chlorinated impurity 0.3 30% (relative) 0.21 0.39 0.0024 0.0046
Di-chlorinated impurity 0.6 20% (relative) 0.48 0.72 0,0049 0.0074
Chloride 6.21 2% (relative) 6.09 6.33 0.3338 0.3500
Chloride 5.82 2% (relative) 5.70 5.94 0.3124 0.3283
Chloride 6.03 2% (relative) 5.91 6.15 0.3239 0.3399
%N recalculated 19.327 (e) \( \frac{\left|r1-e\right|+\left|r2-e\right|}{2} \)= ± 0.038% (relative) 19.365** (r1) 19.289*** (r2)  
Titration* based on Nitrogen content 91.72 0.038% (relative) 91.68 91.75  
  1. *Titration calculation (see previous paragraph)
  2. **%N recalculated with each value of the different contents of the same column
  3. ***%N recalculated with each value of the different contents of the same column