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Abstract: HPLC, HPLC-electrospray ionization (LC-ESI), and LC-FABMS were used to characterize flavonoid glycosides in the methanol extract from peanut meal. Five isoflavones, diadzin, glycitin, genistin, daidzein, and genistein, were separated by HPLC and characterized by comparison with known standards using ESI-MS. The flavonoid methylquercetin (rhamnetin) was present in the methanol extract from peanuts and identified by ESI-MS. Four other flavonoids, two quercetin diglycosides, one quercetin monoglucoside, and isorhamnetin glucoside, were found to be present in the methanol extract based on their reversed-phase elution pattern, mass ions, and fragment ions using flow-FABMS.

HPLC, HPLC-electrospray ionization (LC-ESI), and LC-FABMS were used to characterize flavonoid glycosides in the methanol extract from peanut meal. Five isoflavones, diadzin, glycitin, genistin, daidzein, and genistein, were separated by HPLC and characterized by comparison with known standards using ESI-MS. The flavonoid methylquercetin (rhamnetin) was present in the methanol extract from peanuts and identified by ESI-MS. Four other flavonoids, two quercetin diglycosides, one quercetin monoglucoside, and isorhamnetin glucoside, were found to be present in the methanol extract based on their reversed-phase elution pattern, mass ions, and fragment ions using flow-FABMS.

A low-cost laboratory extractor has been designed and constructed that selectively extracts polar and nonpolar components from oilseeds and other matrices. The extractor uses available high-performance liquid chromatography laboratory equipment for pumping the solvent into the extractor. Pressure, temperature, and valving arrangements are automatically controlled by commercially available components. Advantages of this system include low initial investment, reduced solvent consumption, shorter extraction times, quantitative lipid recovery, use of multiple extraction solvents, and reduction in cost per sample. The method has broader applications that include extraction of trace components from a variety of matrices, for example, the extraction of pesticides from foods and polychlorobiphenyls from soil. Class separation of components from different matrices can be achieved easily by selection of solvents with the appropriate polarity characteristics. Very small samples can be extracted simply by changing cell size or by adding an inert material to the cell to fill the void volume. Analyte collection can be accomplished by collecting in a test tube with an appropriate solvent, or on a solid-phase material. Optimization of extraction times, number of extractions, matrices, and solvent used is described. Neutral lipids were extracted from peanut meal in 70 min by the rapid extraction method compared to 1440 min required to extract the comparable amount of neutral lipids from a similar sample by the Soxhlet extraction method.

A low-cost laboratory extractor has been designed and constructed that selectively extracts polar and nonpolar components from oilseeds and other matrices. The extractor uses available high-performance liquid chromatography laboratory equipment for pumping the solvent into the extractor. Pressure, temperature, and valving arrangements are automatically controlled by commercially available components. Advantages of this system include low initial investment, reduced solvent consumption, shorter extraction times, quantitative lipid recovery, use of multiple extraction solvents, and reduction in cost per sample. The method has broader applications that include extraction of trace components from a variety of matrices, for example, the extraction of pesticides from foods and polychlorobiphenyls from soil. Class separation of components from different matrices can be achieved easily by selection of solvents with the appropriate polarity characteristics. Very small samples can be extracted simply by changing cell size or by adding an inert material to the cell to fill the void volume. Analyte collection can be accomplished by collecting in a test tube with an appropriate solvent, or on a solid-phase material. Optimization of extraction times, number of extractions, matrices, and solvent used is described. Neutral lipids were extracted from peanut meal in 70 min by the rapid extraction method compared to 1440 min required to extract the comparable amount of neutral lipids from a similar sample by the Soxhlet extraction method.

Total lipid extracts from peanut seed were separated on a silica column into a triacylglycerol fraction and a polar lipid fraction by high-performance liquid chromatography (HPLC). The polar fraction containing the phospholipids was retained on the precolumn, and the triacylglycerol fraction was eluted to a waste flask by a special valve arrangement. Phospholipids were eluted from the precolumn and separated into various classes on a silica analytical column. Each phospholipid class was manually collected and subsequently subjected to reversed-phase HPLC in tandem with a fast atom bombardment mass spectrometer. Phosphatidylethanolamine was separated into five molecular species. Phosphatidylinositol and phosphatidylcholine were each separated into six molecular species.

Total lipid extracts from peanut seed were separated on a silica column into a triacylglycerol fraction and a polar lipid fraction by high-performance liquid chromatography (HPLC). The polar fraction containing the phospholipids was retained on the precolumn, and the triacylglycerol fraction was eluted to a waste flask by a special valve arrangement. Phospholipids were eluted from the precolumn and separated into various classes on a silica analytical column. Each phospholipid class was manually collected and subsequently subjected to reversed-phase HPLC in tandem with a fast atom bombardment mass spectrometer. Phosphatidylethanolamine was separated into five molecular species. Phosphatidylinositol and phosphatidylcholine were each separated into six molecular species.

Abstract: Peanuts are harvested in late September, and sometimes the harvest season can extend through most of October. When weather patterns delay harvest, the result may cause an immature crop, curing problems, rain damage, and freeze damage. All of the above stress situations can affect oil quality and flavor of the peanuts by altering phospholipid composition. Such changes are related to refining problems as well as flavor problems. A new high-performance liquid chromatography (HPLC) method was used for the analysis of phospholipids from postharvest stressed peanuts. The concentrations of phosphatidic acid (PA), phosphatidylethanolamine (PE), and phosphatidylcholine (PC) were higher in immature seed when compared to mature seed. A slight increase in concentration was observed for phosphatidylglycerol (PG), and a decrease in phosphatidylinositol occurred in immature peanuts. All phospholipids increased in concentration except PG when peanuts were cured at a high temperature (40C). When peanut seeds were frozen at −16C (before curing), a significant increase in concentration was observed for PA and PG, whereas the concentrations of PC and PE decreased to very low levels when compared to the control. Where concentration permitted, molecular species were separated on a reverse-phase column by HPLC.

Peanuts are harvested in late September, and sometimes the harvest season can extend through most of October. When weather patterns delay harvest, the result may cause an immature crop, curing problems, rain damage, and freeze damage. All of the above stress situations can affect oil quality and flavor of the peanuts by altering phospholipid composition. Such changes are related to refining problems as well as flavor problems. A new high-performance liquid chromatography (HPLC) method was used for the analysis of phospholipids from postharvest stressed peanuts. The concentrations of phosphatidic acid (PA), phosphatidylethanolamine (PE), and phosphatidylcholine (PC) were higher in immature seed when compared to mature seed. A slight increase in concentration was observed for phosphatidylglycerol (PG), and a decrease in phosphatidylinositol occurred in immature peanuts. All phospholipids increased in concentration except PG when peanuts were cured at a high temperature (40°C). When peanut seeds were frozen at -16°C (before curing), a significant increase in concentration was observed for PA and PG, whereas the concentrations of PC and PE decreased to very low levels when compared to the control. Where concentration permitted, molecular species were separated on a reverse-phase column by HPLC.

There is a need for standardized methods for testing vehicle seats. Such methods would allow for the direct comparison of the merits of seats of diverse types and designs. At the present time standardized testing procedures are not possible because the dynamic characteristics of the human subjects occupying the seat during testing vary widely from man to man and affect the seat response. Testing with dead weight loading does not accurately portray the dynamic characteristics of the seat. A damped spring-mass system closely approximating to the dynamic characteristics of a seated man to vertical modes of vibration has been developed as the basis on which a standardized vehicle seat testing procedure can be built. Analysis of the problem by means of mechanical impedance techniques indicated that a two-degree-of-freedom system was sufficient to simulate the major dynamic characteristics of man in the frequencies below 10 Hz where seat vibration is most severe. Test procedures have been developed which utilize the man-simulator as the seat load. Results of these tests will be useful because they do not contain the subject variable and therefore can be compared directly with results obtained in other laboratories using the same methods.

Abstract: This paper discusses the details of a high-performance liquid chromatography method for the simultaneous concentration and separation of phospholipids or other trace compounds by direct oil injection using two different solvent systems. The system equilibrates and concentrates phospholipids on a silica column using hexane. At the same time, an analytical column is equilibrating and separating phospholipids using two binary solvent mixtures. This system eliminates a preconcentration step previously accomplished by solid-phase extraction, open-column chromatography, and other previously used methodology. Other advantages include: a 40% reduction in analysis time, elimination of a second transfer of labile compounds, decreased solvent use, and a simpler array of solvents to separate phospholipids. The method described has broader applications, such as trace organic compounds in water supplies, and trace metals with appropriate modifications for the particular analysis.

This paper discusses the details of a high-performance liquid chromatography method for the simultaneous concentration and separation of phospholipids or other trace compounds by direct oil injection using two different solvent systems. The system equilibrates and concentrates phospholipids on a silica column using hexane. At the same time, an analytical column is equilibrating and separating phospholipids using two binary solvent mixtures. This system eliminates a preconcentration step previously accomplished by solid-phase extraction, open-column chromatography, and other previously used methodology. Other advantages include: a 40% reduction in analysis time, elimination of a second transfer of labile compounds, decreased solvent use, and a simpler array of solvents to separate phospholipids. The method described has broader applications, such as trace organic compounds in water supplies, and trace metals with appropriate modifications for the particular analysis.