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This week on Bench Boost we discuss titration techniques based on USP 541 and the Inorganic Venture's Titration Tips and Tricks guide. Mike explains the difference between equivalence point and observed endpoint and how key performance factors can include using the correct glassware, appropriate techniques, and thorough cleaning of burettes. We also cover the correct way to read a meniscus, and how optimizing sample size can prevent poor replicate agreement and high result variability.

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This week on Bench Boost Mike explains why accurate pH measurement is more complex than it appears, highlighting the effects from temperature, ionic strength, calibration technique, probe condition, and sample chemistry. He reviews pH theory of hydrogen ion activity (not just concentration) and the logarithmic meaning of pH changes, then describes how a pH probe functions as an electrochemical cell. He details temperature impacts on solution pH and electrode response (Nernst slope), notes automatic temperature compensation limits, summarizes USP <791> calibration buffers and allowable uncertainty.

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This week on Bench Boost Mike shares practical tips for analyzing pharmaceutical samples at low concentrations for USP 232 elemental impurities, emphasizing that high dilution makes small contamination or carryover issues critical. He advises minimizing contamination through careful container selection (avoiding glass and using acid-leached LDPE or leached polypropylene), and outlines a typical leaching process using dilute nitric acid for seven days. He also stresses using high-purity acids (ppb/ppt grade) and method blanks to monitor impurities. For trace measurements, he recommends tightening calibration ranges with more points near the LOD/LOQ, managing washout by running blanks before/after calibration and throughout batches, using appropriate internal standards to correct drift or suppression, recalibrating about every 20 samples, and understanding signal-to-noise requirements for LOD and LOQ.