Supercritical uid extraction (SFE) has been developed as a technique which can lead to rapid,selective extraction from a variety of matrices under conditions which are much milder than those neededfor solvent extraction4;910. Smith and Burford10have reported SFE studies on feverfew samples, withGC analysis of the extracts. These showed that supercritical carbon dioxide could be used to extractsesquiterpene lactones, and they investigated methods of optimising the extraction process. As their GCanalysis used ame ionisation detection, however, determination of the separated components of the extractwas not possible, although parthenolide itself could be identied by comparison with a standard sample.Supercritical uid chromatography (SFC) is particularly useful for the analysis of thermally sensitivematerials, and it can also be interfaced to a range of spectroscopic detectors to identify individual membersof complex mixtures9;1114. There have been a number of published applications of SFC to the analysisof natural products and foodstus, including polyprenols in Gingko biloba leaves15, triglycerides in Aqui-legia vulgaris16, an SFC-UV-FTIR-FID study on extracts from an Azeri plant of the genus Ferula17, andtriglycerides from a variety of cheeses18.We have therefore conducted an extension .High performance liquid chromatography (HPLC) and supercritical uid chromatography (SFC)analyses are used to show that supercritical uid extraction (SFE) using carbon dioxide is an eectivemeans of extracting a range of components from feverfew samples. It was found that the speciccompositions of solvent extracts and SFE extracts are dierent. The amounts of the presumed activeingredient parthenolide have been conrmed to be very variable. Feverfew seeds were particularly rich inparthenolide, while dried powdered samples contained less and, in one case, none at all. The tunabilityof SFE has been demonstrated, and it was shown that successive extractions at 100 and 200 atm separatethe extracted components into two mutually exclusive groups, with important implications for simplifyingsubsequent analyses. Analytical chemistry is the study of the separation, identification, and quantification of the chemical components of natural and artificial materials. Qualitative analysis gives an indication of the identity of the chemical species in the sample and quantitative analysis determines the amount of one or more of these components. The separation of components is often performed prior to analysis. Analytical methods can be separated into classical and instrumental. Classical methods (also known as wet chemistry methods) use separations such as precipitation, extraction, and distillation and qualitative analysis by color, odor, or melting point. Quantitative analysis is achieved by measurement of weight or volume. Instrumental methods use an apparatus to measure physical quantities of the analyte such as light absorption, fluorescence, or conductivity. The separation of .

1. Supercritical uid extraction (SFE) has been developed as a technique which can lead to
rapid,selective extraction from a variety of matrices under conditions which are much milder
than those neededfor solvent extraction4;910. Smith and Burford10have reported SFE studies on
feverfew samples, withGC analysis of the extracts. These showed that supercritical carbon
dioxide could be used to extractsesquiterpene lactones, and they investigated methods of
optimising the extraction process. As their GCanalysis used ame ionisation detection, however,
determination of the separated components of the extractwas not possible, although parthenolide
itself could be identied by comparison with a standard sample.Supercritical uid chromatography
(SFC) is particularly useful for the analysis of thermally sensitivematerials, and it can also be
interfaced to a range of spectroscopic detectors to identify individual membersof complex
mixtures9;1114. There have been a number of published applications of SFC to the analysisof
natural products and foodstus, including polyprenols in Gingko biloba leaves15, triglycerides in
Aqui-legia vulgaris16, an SFC-UV-FTIR-FID study on extracts from an Azeri plant of the genus
Ferula17, andtriglycerides from a variety of cheeses18.We have therefore conducted an
extension
.High performance liquid chromatography (HPLC) and supercritical uid chromatography
(SFC)analyses are used to show that supercritical uid extraction (SFE) using carbon dioxide is an
eectivemeans of extracting a range of components from feverfew samples. It was found that the
speciccompositions of solvent extracts and SFE extracts are dierent. The amounts of the
presumed activeingredient parthenolide have been conrmed to be very variable. Feverfew seeds
were particularly rich inparthenolide, while dried powdered samples contained less and, in one
case, none at all. The tunabilityof SFE has been demonstrated, and it was shown that successive
extractions at 100 and 200 atm separatethe extracted components into two mutually exclusive
groups, with important implications for simplifyingsubsequent analyses.
Analytical chemistry is the study of the separation, identification, and quantification of the
chemical components of natural and artificial materials. Qualitative analysis gives an indication
of the identity of the chemical species in the sample and quantitative analysis determines the
amount of one or more of these components. The separation of components is often performed
prior to analysis.
Analytical methods can be separated into classical and instrumental. Classical methods (also
known as wet chemistry methods) use separations such as precipitation, extraction, and
distillation and qualitative analysis by color, odor, or melting point. Quantitative analysis is
achieved by measurement of weight or volume. Instrumental methods use an apparatus to
measure physical quantities of the analyte such as light absorption, fluorescence, or conductivity.
The separation of materials is accomplished using chromatography or electrophoresis methods.

2. Analytical chemistry is also focused on improvements in experimental design, chemometrics,
and the creation of new measurement tools to provide better chemical information. Analytical
chemistry has applications in forensics, bioanalysis, clinical analysis, environmental analysis,
and materials analysis.
Solution
Supercritical uid extraction (SFE) has been developed as a technique which can lead to
rapid,selective extraction from a variety of matrices under conditions which are much milder
than those neededfor solvent extraction4;910. Smith and Burford10have reported SFE studies on
feverfew samples, withGC analysis of the extracts. These showed that supercritical carbon
dioxide could be used to extractsesquiterpene lactones, and they investigated methods of
optimising the extraction process. As their GCanalysis used ame ionisation detection, however,
determination of the separated components of the extractwas not possible, although parthenolide
itself could be identied by comparison with a standard sample.Supercritical uid chromatography
(SFC) is particularly useful for the analysis of thermally sensitivematerials, and it can also be
interfaced to a range of spectroscopic detectors to identify individual membersof complex
mixtures9;1114. There have been a number of published applications of SFC to the analysisof
natural products and foodstus, including polyprenols in Gingko biloba leaves15, triglycerides in
Aqui-legia vulgaris16, an SFC-UV-FTIR-FID study on extracts from an Azeri plant of the genus
Ferula17, andtriglycerides from a variety of cheeses18.We have therefore conducted an
extension
.High performance liquid chromatography (HPLC) and supercritical uid chromatography
(SFC)analyses are used to show that supercritical uid extraction (SFE) using carbon dioxide is an
eectivemeans of extracting a range of components from feverfew samples. It was found that the
speciccompositions of solvent extracts and SFE extracts are dierent. The amounts of the
presumed activeingredient parthenolide have been conrmed to be very variable. Feverfew seeds
were particularly rich inparthenolide, while dried powdered samples contained less and, in one
case, none at all. The tunabilityof SFE has been demonstrated, and it was shown that successive
extractions at 100 and 200 atm separatethe extracted components into two mutually exclusive
groups, with important implications for simplifyingsubsequent analyses.
Analytical chemistry is the study of the separation, identification, and quantification of the
chemical components of natural and artificial materials. Qualitative analysis gives an indication
of the identity of the chemical species in the sample and quantitative analysis determines the
amount of one or more of these components. The separation of components is often performed
prior to analysis.

3. Analytical methods can be separated into classical and instrumental. Classical methods (also
known as wet chemistry methods) use separations such as precipitation, extraction, and
distillation and qualitative analysis by color, odor, or melting point. Quantitative analysis is
achieved by measurement of weight or volume. Instrumental methods use an apparatus to
measure physical quantities of the analyte such as light absorption, fluorescence, or conductivity.
The separation of materials is accomplished using chromatography or electrophoresis methods.
Analytical chemistry is also focused on improvements in experimental design, chemometrics,
and the creation of new measurement tools to provide better chemical information. Analytical
chemistry has applications in forensics, bioanalysis, clinical analysis, environmental analysis,
and materials analysis.