摘要:
A method for analyzing a gas sample is described (10). The method comprises providing a gas sample, increasing pressure applied to the gas sample to compress the sample to a smaller volume and provide a pneumatically focused gas sample, and analyzing the pneumatically focused gas sample using any of a variety of analytical techniques. Pneumatic Focusing generally means increasing the pressure of the sample, column or cell to a pressure of from about 100 psi to about 15,000 psi, more typically from about 200 psi to about 2,000 psi. Examples including gas chromatography and absorption spectroscopy are illustrated herein. Numerous other examples could be given. The method is well suited for analyzing gaseous samples, such as ambient air samples, both continuously, and remotely, using computer control. Continuously sampling ambient air provides a method for real-time monitoring of air quality. Continuous monitoring (58) allows for pollutant exposure and allows for the identification of emission sources. The method is also well suited for analysis of breath exhalations from respiring organisms useful in metabolic studies or disease diagnosis.
摘要:
A method and apparatus are provided for identifying peaks in spectral data. A method in accordance with some embodiments includes sorting the spectral data by spectral parameter values; detecting peaks in the data; integrating peak areas; identifying any coeluting peaks, and combining coeluting peak areas determined to be associated with the same compound; and generating a list of detected peaks and their corresponding areas, including any combined coeluting peak areas.
摘要:
The method comprises a simple headspace sampling and GC-MS analysis of samples of the test material. A statistically significant comparison between samples is obtained by calibration with reference samples that ensure reproducibility of the results against a possible change in sensitivity of the gas chromatographic instrument. The method is quick to perform as the data obtained are analysed by integrating areas of a chromatogram without identifying and assigning each chromatographic peak individually.
摘要:
Components resolved in time by a separator accumulate in a sample cell and are analyzed by electromagnetic radiation-based spectroscopic techniques. The sample cell can be configured for multiple path absorption and can be heated. The separator can be a gas chromatograph or another suitable device, for example a distillation-based separator. The method and system described herein can include other mechanical elements, controls, procedures for handling background and sample data, protocols for species identification and/or quantification, automation, computer interfaces, algorithms, software or other features.
摘要:
The application describes a method for predicting chemical or biological properties, e.g. toxicity, mutagenicity, etc., of complex multicomponent mixtures from 2D separation date, e.g. GC-MS. The data are resolved into peaks (C) and spectra (S) for individual components by an automated curve resolution procedure (GENTLE). The resolved peaks are then integrated and the characteristic area, separation parameter and associated spectrum combined to yield a predictor matrix (X), which is used as input to a multivariate regression model. Partial least squares (PLS) are used to correlate the 2D separation date for a training set to the measured property. The regression model can then be used to predict the property for other samples.
摘要:
A method for analyzing a gas sample is described (10). The method comprises providing a gas sample, increasing pressure applied to the gas sample to compress the sample to a smaller volume and provide a pneumatically focused gas sample, and analyzing the pneumatically focused gas sample using any of a variety of analytical techniques. Pneumatic Focusing generally means increasing the pressure of the sample, column or cell to a pressure of from about 100 psi to about 15,000 psi, more typically from about 200 psi to about 2,000 psi. Examples including gas chromatography and absorption spectroscopy are illustrated herein. Numerous other examples could be given. The method is well suited for analyzing gaseous samples, such as ambient air samples, both continuously, and remotely, using computer control. Continuously sampling ambient air provides a method for real-time monitoring of air quality. Continuous monitoring (58) allows for pollutant exposure and allows for the identification of emission sources. The method is also well suited for analysis of breath exhalations from respiring organisms useful in metabolic studies or disease diagnosis.