Free pharmacy material Sulphonamides, Sulphones, and Dihydrofolate Reductase Inhibitors The sulphonamides are synthetic bacteriostatic antibiotics with a wide spectrum against most gram-positive and many gram-negative organisms. The sulphonamides and sulphone antibacterials as well as the 2,4-diaminopyrimidine antifolates continue to be successful chemotherapeutic agents. 24.1 SULPHONAMIDES The sulphonamide drugs were the first effective chemotherapeutic agents to be employed systemically for the prevention of bacterial infections in human beings. These are totally synthetic substances that are produced by relatively simple chemical synthesis. Sulphonamide drugs are a group of synthetic antimicrobial drugs that have a broad spectrum of use with respect to grampositive as well as gram-negative micro-organisms. They were introduced into medical practice even before the discovery of penicillins. Sulphonamide drugs are derivatives of sulphanilamide. The advent of penicillin and s...
⚠️ Common HPLC Problems & Troubleshooting 1. High Back Pressure 🚧 Possible causes Blocked column Dirty mobile phase Blocked inline filter Precipitated buffer salts Troubleshooting Flush column with strong solvent (e.g., high % organic) Replace guard column or inline filter Filter and degas mobile phase (0.45 µm or 0.22 µm) Check tubing for blockage --- 2. Low Pressure 📉 Possible causes Leak in system Pump seal worn out Empty solvent reservoir Air in pump Troubleshooting Check for leaks in fittings Prime the pump properly Replace pump seals Ensure solvent bottle has enough mobile phase --- 3. Baseline Noise 🔊 Possible causes Air bubbles in detector Dirty flow cell Poor degassing Contaminated mobile phase Troubleshooting Degas mobile phase (sonication or helium sparging) Clean detector flow cell Purge detector Use fresh solvents --- 4. Baseline Drift 📈 Possible causes Temperature fluctuations Mobile phase composition change Column not equilibrated Detector lamp aging Troubleshoot...