ACD/Structure Elucidator

UV-Vis, IR, and Raman List of Processing Features

• Convert the vertical axis units between Absorbance, Transmittance, % Transmittance, simple and Logarithmic Molar Absorptivity (for absorption spectra) or Reflectance, % Reflectance, Kubelka-Munk, or Log(1/R) (for reflectance spectra).
• Correct the spectrum for a baseline that can be detected automatically or manually constructed.
• Interactively remove noise from your spectroscopic data with a flexible FFT or Savitsky-Golay smoothing algorithms.
• Perform simple arithmetic operations between a spectrum/series and a constant.
• Subtract a scaled spectrum from another spectrum or series; automatically subtract a component signal from a mixture spectrum.
• Cut off a selected part of the spectrum.
• Interactively convert a spectrum into its 1^st, 2^nd, 3^rd, or 4^th derivatives.
• Perform ATR (attenuated total reflectance) correction to remove the effect of varied penetration depth.
• De-resolve a spectrum or enhance its resolution.
• Interpolate an entire spectrum or a series to another custom X-grid.
• Average a spectral series to obtain the "mean" spectrum.
• Zoom in on any area.
• Switch between different spectral units (cm^-1, nanometers, micrometers, or points).
• Easily locate the position of a spectrum feature using an "intelligent" vertical cursor.
• Calculate up to the 4^th order derivative of a spectrum; the derivative spectrum will be overlaid on the original spectrum.
• Automatic or manual peak picking will autogenerate a table of peaks.
• Calculate peak areas and their FWHH (full width at half-height) and asymmetry values.
• Peak Fitting of overlapped spectral peaks as a sum of Gauss, Lorentz, Gauss+Lorentz, or asymmetric LogNormal functions.
• Annotate peaks or spectral regions with descriptive notes.
• Interactively assign peaks to chemical structural fragments and autogenerate a table of assignments.
• Verify whether an attached chemical structure corresponds to the peaks in the spectrum, and vice versa. The verification tool is based on an original technology from ACD/Labs using an internal knowledge base of IR characteristic group frequencies for over one thousand fragments. It combines information that was carefully collected from many sources, and then refined by testing with quality experimental spectra databases. The database contents can be browsed and searched. It can also serve as an effective reference information source.
• Perform color analysis of spectra in the visible light region to calculate color parameters; predict sample color and mark it as a point on the CIE diagram (International Commission on Illumination).
• Perform a quantitative analysis for a series of spectra: obtain a calibration line by plotting the spectral responses vs. a variable parameter such as concentration; this analysis provides a comprehensive set of statistics; this calibration can be then saved and used for prediction or copied to the ACD/Curve Processor for advanced treatment and polynomial regression analysis.
• SIMPLISMA (SIMPLe-to-use Interactive Self-modeling Mixture Analysis) is an up-to-date chemometrics technique for the curve resolution problem. The algorithm is applied to a series of mixture spectra where component concentrations are varied (e.g., as a result of a process evolving in time). It allows a scientist to reconstruct spectral shapes of pure mixture components and their relative concentrations without requiring any additional information. The number of mixture components is also obtained as a result of the analysis. The main advantage of SIMPLISMA is its high interactivity which allows the user to keep control over the entire process obtaining the best result.