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.
Chromatography Terms
HPLC Column Cleaning: How to Diagnose Contamination, Clean Safely, and Verify Recovery
Do not clean an HPLC column simply because pressure, retention or peak shape changed. First rule out the system, mobile phase, sample,…
Molarity of 37% (w/w) Hydrochloric Acid (HCl) — Value & Calculator
Concentrated hydrochloric acid at 37% (w/w) is approximately 12.2 M. Using M = (10 × %w/w × density) ÷ molar mass, with…
Molecular and Equivalent Weights of Common Compounds
Chemical Name Molecular Formula Molecular Weight (g/mol) Equivalent Weight (g/equiv) Acetic Acid CH3COOH 60.05 60.05 Ammonium Sulfate (NH4)2SO4 132.14 132.14 Calcium Carbonate…
Preparation of 0.25 M Sodium Hydroxide (NaOH) Solution
Overview Calculation procedure Parameter Value Required volume 1000 mL Molecular weight of NaOH 39.997 g/mol Concentration of 0.25 M Sodium Hydroxide 1.00%…
Preparation of 2X YT Media
Overview Reagents Required Equipment Preparation Step 1: To prepare 1000 ml of 2 X YT medium, weigh out 16 g tryptone, 10…
HPLC Peak Shape Problems: Tailing, Fronting, Splitting and Broadening
Splitting, fronting, tailing or broadening? Identify the peak shape first, then work the likely causes in order. A practical HPLC diagnostic guide…