Analytical Methods
Overview of the methods used for batch-release testing of SR-17018 by our ISO 17025-accredited partner laboratory. All methods are validated for the intended purpose prior to use in batch release. Representative parameters are shown; contact us for full method documentation.
HPLC-UVPurity Determination
ColumnC18 reverse-phase, 150 × 4.6 mm, 3.5 μm particle size
Mobile PhaseGradient: 0.1% TFA in water / acetonitrile
Detection Wavelength254 nm
Flow Rate1.0 mL/min
Run Time20 minutes
System SuitabilityUSP tailing factor ≤2.0, plate count ≥5000 for principal peak, %RSD of area ≤2.0% (n=5)
Acceptance CriterionPurity ≥99.0% (area normalisation, excluding solvent front)
LC-MS/MSIdentity Confirmation
InstrumentTriple-quadrupole LC-MS/MS (representative: Sciex API 4000)
Ionisation ModeElectrospray ionisation, positive mode (ESI+)
Precursor Ion [M+H]⁺m/z 491.0 (nominal)
Key Fragment Ionsm/z 325.0, 289.0, 253.0 (representative)
Acceptance CriterionObserved molecular ion consistent with MW 490.22; fragment ion pattern consistent with reference standard
¹H-NMRStructural Verification
Field Strength400 MHz
SolventDMSO-d6
ReferenceResidual solvent peak (DMSO: δ 2.50 ppm)
Key Diagnostic PeaksAromatic protons δ 8.2–8.6 ppm; NH protons δ 9.0–10.0 ppm (broad, exchangeable)
Acceptance CriterionSpectrum consistent with proposed structure; integration ratios consistent with molecular formula C₂₁H₁₆Cl₄N₄
Karl Fischer TitrationMoisture Content
MethodCoulometric Karl Fischer titration (volumetric for larger samples)
ReagentHydranal-Composite 5 (or equivalent)
Sample PreparationDissolve accurately weighed sample in anhydrous methanol
Endpoint DetectionBiamperometric
Acceptance CriterionWater content ≤1.0% w/w
ISO 17025 Accreditation: All batch-release testing is performed by an accredited partner laboratory operating under ISO/IEC 17025:2017. Accreditation scope covers the methods listed above as applied to research chemical purity and identity testing. Certificates of accreditation are available upon request.