Quantitative Analysis of High-Concentration Samples without Dilution ―Introducing the UV-2700i Plus―

User Benefits

- With its double monochromator and low stray light diffraction gratings, the UV-2700i Plus can analyze high-concentration samples at up to 8 Abs without dilution or other sample preparation steps. - The spectrum-based quantitative analysis feature enables viewing and considering the entire absorbance spectrum during quantitative analysis.

Introduction

UV-Vis spectrophotometers are used for quantitative analysis of analytes in solutions or to assess optical components. When quantitatively analyzing analytes in solutions, UV-Vis spectrophotometers measure absorbance since this varies proportionally with analyte concentrations. However, at absorbances greater than 2 Abs, most UV-Vis spectrophotometers cannot maintain the linear relationship between analyte concentrations and absorbance due to the impact of stray light (light outside the wavelength that is being used for analysis). This can be addressed by diluting the sample, which reduces the concentration of the analyte to a level that can be measured by the instrument. (For solids, the sample is cut into a thin section.) The UV-2700i Plus UV-Vis spectrophotometer, however, has two diffraction gratings (a double monochromator) that diffract light and uses low stray light diffraction gratings that enable it to measure absorbances of up to 8 Abs.* This wide dynamic range makes it suitable for quantitatively analyzing samples that are not easy to dilute and for assessing the transmission characteristics of low-transmission samples. This Application News article describes using the UV-2700i Plus to analyze a high-concentration sample and also the spectrumbased quantitative analysis feature available in LabSolutions UV-Vis, Shimadzu’s control software for UV-Vis spectrophotometers.

February 11, 2025 GMT