The Knowledge Hub
Practical troubleshooting guides for working analytical chemists — HPLC, UHPLC, LC-MS, GC, and reagent prep. Each guide is diagnostic-first and linked to the tool that resolves it.
Ion Exchange Chromatography (IEX): Anion vs Cation, Resin Selection, and Method Setup
How ion exchange chromatography works, when to choose anion vs cation exchange, strong vs weak resins, and how to fix poor binding…
Ion Suppression and Matrix Effects in LC-MS
Ion suppression is a loss of analyte signal caused by co-eluting matrix components competing for charge during electrospray ionisation. It is the…
LC-MS Sensitivity Loss: A Six-Step Diagnostic Checklist
Diagnosing LC-MS sensitivity loss means answering one question first: are analyte molecules failing to reach the source, failing to ionise once there,…
Sulfuric Acid (H2SO4): Density, Molar Mass and Concentration Table
Density of H2SO4 at every concentration from 10% to 98%, with molarity and normality. Molar mass 98.079 g/mol, plus dilution volumes and…
Molar Mass of NaOH (Sodium Hydroxide): Value, Calculation and Lab Use
The molar mass of NaOH is 39.997 g/mol (40.00 g/mol in practice). See the calculation, gram-to-mole conversions, and how much to weigh…
Autosampler Carryover in HPLC and LC-MS: How to Find It and Wash It Out
Carryover is one of the quietest ways an autosampler can wreck your data. A trace of analyte left behind from a previous…
HPLC Baseline Noise and Drift: How to Tell Them Apart and Fix Each
An unstable baseline is one of the most common — and most time-consuming — problems in HPLC; by some estimates, baseline issues…
Ghost Peaks in HPLC: What Causes Them and How to Eliminate Them
You inject a blank — pure solvent, no sample — and peaks appear anyway. Or your gradient runs show extra peaks that…
Why Your HPLC Peaks Are Tailing: Causes and a Diagnostic Path
Peak tailing is one of the most common complaints in HPLC — and one of the most misdiagnosed. A tailing peak inflates…
High Backpressure in HPLC: 8 Root Causes and How to Diagnose Each One
High system backpressure is one of the most common — and most disruptive — problems in liquid chromatography. It interrupts runs, triggers…
Signal-to-Noise Ratio for LOD: How to Measure and Use It in Chromatography
connectivity probe
LOD Calculation: How to Determine the Limit of Detection Using ICH Q2 Methods
The limit of detection is calculated as LOD = 3.3σ/S, where σ is the standard deviation of the response and S is…