ChemScience Inc

Spectrophotometric analysis does not begin when a prepared solution reaches the instrument. The reliability of the final absorbance measurement also depends on what occurred during the preceding stages of quantitative analysis. The analytical concentration, preparation of the standards, dilutions, solvents etc. can all impact the final value. Volumetric Flasks are an important element of this preparation stage as they are used to define the end volume. If a method calls for the preparation of standards and/or stock solutions or the dilution of a sample to a desired concentration, the capability of bringing a solution to a desired volume serves as a basis for reproducible quantitative work. This is especially important because an instrument can accurately measure the absorbance of a solution even when the concentration assigned to that solution is incorrect. Accurate instrument readings cannot compensate for an incorrectly prepared standard used to construct a calibration curve. Therefo...

Sound analytical testing starts prior to a sample coming into contact with an instrument. The quality of the end result can be affected by the sample collection, storage, preparation and filtration. Unwanted particulate matter, suspended solids, aggregates or microorganisms may interfere with sample handling even when the analytical method and instrument is controlled properly and in some workflows, interfere with instrument performance. Membrane Filters provide a controlled means of removing particulate material from liquid samples. Membrane filtration may be applied for sample clarification, analytical sample preparation, microbial retention and protection of sensitive analytical systems, depending on membrane chemistry, pore characteristics and device format. However, filtration is only one part of the analytical process; selecting a suitable membrane and controlling the filtration procedure are essential to improve sample quality without compromising analyte recovery. What are Mem...