Research Library
Analytical Testing
COA review, HPLC, LC-MS, mass spectrometry, chromatograms, and data interpretation.
34 articles
12 min · Aug 14, 2026
HPLC vs. Mass Spectrometry: What Each Method Tells YouA practical comparison of HPLC and mass spectrometry for peptide analysis—what each method measures, what it cannot prove alone, and why they are complementary.
11 min · Aug 14, 2026
Purity and Identity Are Not the SameWhy chromatographic purity and molecular identity answer different analytical questions, and why peptide COA review should treat them as complementary evidence.
12 min · Jul 31, 2026
A Strategy for Peptide Sequence ConfirmationHow intact mass, MS/MS, peptide mapping, composition, and orthogonal methods combine to support peptide sequence identity.
10 min · Jul 31, 2026
Accuracy vs. Precision in Peptide TestingWhy closeness to the true value differs from repeatability and how both are evaluated in analytical validation.
11 min · Jul 31, 2026
Adduct Formation in Peptide Mass SpectrometryHow sodium, potassium, solvents, acids, and matrix components create additional peptide mass-spectral signals.
11 min · Jul 31, 2026
Amino Acid Analysis for Peptide CharacterizationHow hydrolysis, derivatization, separation, and detection are used to assess amino-acid composition and support peptide content.
11 min · Jul 31, 2026
Analytical Specificity for Peptide MethodsHow a method distinguishes the target peptide from impurities, degradants, excipients, and matrix components.
11 min · Jul 31, 2026
Chromatographic Resolution ExplainedHow resolution describes separation between peptide peaks and how selectivity, efficiency, and retention influence it.
12 min · Jul 31, 2026
Chromatography Fundamentals for Peptide AnalysisA foundational guide to retention, selectivity, efficiency, resolution, mobile phase, and stationary phase behavior in peptide chromatography.
11 min · Jul 31, 2026
Detector Linearity in Peptide AnalysisHow analytical response should relate to concentration and why residuals, weighting, and range matter more than correlation alone.
11 min · Jul 31, 2026
How to Interpret a Peptide HPLC ChromatogramA practical guide to chromatogram axes, retention time, peak area, resolution, integration, system suitability, and common artifacts.
12 min · Jul 31, 2026
How to Investigate an Unknown HPLC PeakAn evidence-based workflow for characterizing new or unexpected peaks in peptide testing.
12 min · Jul 31, 2026
How to Read a Peptide Certificate of AnalysisA field-by-field guide to peptide COAs, including identity, purity, assay, method details, specifications, signatures, and common warning signs.
14 min · Jul 31, 2026
HPLC Method Development for Peptide AnalysisA structured approach to defining method goals, screening columns, optimizing gradients, and resolving critical peptide impurities.
13 min · Jul 31, 2026
HPLC Peptide Purity Testing ExplainedHow reversed-phase HPLC separates peptide components, how chromatographic purity is calculated, and why method suitability matters.
11 min · Jul 31, 2026
Isotopic Distributions in Peptide Mass SpectrometryHow natural isotopes create peptide isotope envelopes and how monoisotopic and average masses differ.
12 min · Jul 31, 2026
LC-MS vs. MALDI-TOF for Peptide CharacterizationHow LC-MS and MALDI-TOF differ in ionization, workflow, quantitation, impurity profiling, throughput, and peptide identity testing.
12 min · Jul 31, 2026
Limit of Detection and Limit of QuantitationHow LOD and LOQ are established for peptide methods and why visual detection is different from reliable quantitation.
10 min · Jul 31, 2026
Mass Accuracy in Peptide Mass SpectrometryHow calibration, resolution, charge assignment, and processing affect the difference between observed and theoretical peptide mass.
11 min · Jul 31, 2026
Mass Deconvolution in Peptide AnalysisHow software converts multiply charged peptide spectra into neutral-mass results and where processing errors can occur.
12 min · Jul 31, 2026
Mass Spectrometry for Peptide IdentityHow peptide mass spectrometry works, how charge states are interpreted, and what intact mass can and cannot prove.
12 min · Jul 31, 2026
MS/MS Fragmentation of PeptidesHow peptide ions fragment in tandem mass spectrometry and how product-ion series support sequence interpretation.
11 min · Jul 31, 2026
Peak Integration in HPLCHow chromatographic software defines peak boundaries and why controlled integration is essential for credible peptide purity results.
11 min · Jul 31, 2026
Peak Tailing and Fronting in Peptide HPLCWhy chromatographic peaks become asymmetric and how overload, secondary interactions, and system effects alter peptide results.
11 min · Jul 31, 2026
Peptide Charge States in Electrospray Mass SpectrometryWhy peptides form multiple charged ions and how charge-state assignment supports deconvolution and mass confirmation.
12 min · Jul 31, 2026
Peptide Mapping ExplainedHow enzymatic or chemical digestion and chromatographic analysis create a peptide fingerprint for identity and structural comparison.
11 min · Jul 31, 2026
Recovery Studies in Peptide AnalysisHow spike-recovery and process-recovery experiments reveal losses from extraction, adsorption, filtration, and matrix effects.
11 min · Jul 31, 2026
Robustness Testing for Peptide MethodsHow deliberate small method changes identify critical parameters and operating ranges in peptide analysis.
10 min · Jul 31, 2026
Ruggedness and Intermediate PrecisionHow analysts, instruments, days, columns, and laboratories contribute to real-world method variability.
12 min · Jul 31, 2026
Sample Preparation for Peptide AnalysisHow dissolution, dilution, filtration, adsorption, stability, and container selection influence analytical results.
10 min · Jul 31, 2026
Signal-to-Noise in Chromatographic TestingHow baseline noise and analyte signal affect sensitivity, detection limits, and low-level peptide impurity measurements.
12 min · Jul 31, 2026
System Suitability Testing for Peptide MethodsHow system-suitability criteria verify that an HPLC or LC-MS system is ready to generate acceptable peptide data.
11 min · Jul 31, 2026
UPLC vs. HPLC for Peptide AnalysisA practical comparison of HPLC and UPLC for peptide purity, impurity profiling, transfer, speed, pressure, and method performance.
10 min · Jul 31, 2026
UV Detection in Peptide HPLCHow peptide bonds and aromatic residues absorb ultraviolet light and how wavelength selection affects sensitivity and impurity response.