A simple and green ultra-high-performance micellar liquid chromatography (MLC) method was develop... more A simple and green ultra-high-performance micellar liquid chromatography (MLC) method was developed here, comparing Tween 20 and Tween 40 for the first time as the only mobile phase modifiers with a C18 column. Its application to the separation of nine hydroxycinnamic acid (HCA) derivatives (cinnamic, caffeic, ferulic, sinapic, o-, m-, p-coumaric, 3,4-dihydroxyhydrocinnamic, and chlorogenic acids) was made, due to their importance as antioxidants in a variety of natural beverages such as wine and coffee. The optimal conditions of 45 °C temperature (T), 1% surfactant in the mobile phase, and pH control with 2.5 mM sulfuric acid were determined and used to elucidate the analytical figures of merit. Although the effect of these conditions was insignificant between the two surfactants, the nine-component HCA mixture was separated faster—in about 15 min—and with less peak tailing using Tween 20 than with Tween 40. The linearity of the Van’t Hoff (lnk versus 1/T) plots was evident for Twe...
Abstract The use of polychlorotrifluoroethylene (PCTFE) particles packed in 5–10 cm × 0.4 cm ID c... more Abstract The use of polychlorotrifluoroethylene (PCTFE) particles packed in 5–10 cm × 0.4 cm ID columns for the immobilization of enzymes by hydrophobic adsorption is investigated. Enzyme binding capacity of PCTFE is about 0.2 mg/gm of polymer. PCTFE-immobilized lactate dehydrogenase, alcohol dehydrogenase, and urease-glutamate dehydrogenase are demonstrated to be useful for the determinations of pyruvate, ethanol, and urea, respectively. Immobilized enzyme lifetimes are generally about 1–2 months.
The photochemical activities of six sulfa compounds [sulfacetamide (CET), sulfadiazine (DIA), sul... more The photochemical activities of six sulfa compounds [sulfacetamide (CET), sulfadiazine (DIA), sulfaguanidine (GUA), sulfamerazine (MER), sulfamethoxazole (SMX), and sulfamethizole (MET)] under different experimental conditions such as photolysis time, ...
Hrc-journal of High Resolution Chromatography, May 1, 1992
Page 1. Short Communications separations are performed between 60 and 140 "C, the te... more Page 1. Short Communications separations are performed between 60 and 140 "C, the tempera-ture limitations of these connectors do not seem too restrictive. Deactivation of the quartz couplings was essential for obtaining ...
Journal of Chromatography B: Biomedical Sciences and Applications, Nov 1, 1980
A direct assay for creatine kinase (CK) activity was developed based on the separation and quanti... more A direct assay for creatine kinase (CK) activity was developed based on the separation and quantitation of adenosine triphosphate (ATP) by high-performance liquid chromatography. The total incubation time is 13 min and the elution time for ATP is 16 min. Using lyophilized CK as the sample, a sensitivity in the range of 8 U/l (units/liter) was obtained. The method presented also has clinical significance in that CK levels in serum can easily be determined with minimal sample preparation. Using serum samples from a healthy patient and a heart attack victim, activities of 26.6 U/l and 609.0 U/l, respectively, were obtained. Because of the direct measurement of ATP, this method eliminates the coupled reactions encountered in the common spectrophotometric and colorimetric methods of analysis resulting in a simpler and inexpensive assay.
Industrial & Engineering Chemistry Product Research and Development, Jun 1, 1983
Page 1. Ind. Eng. Chem. Prod. Res. Dev. 1983, 22, 303-307 303 Reactivity of Kel-F Polymers with O... more Page 1. Ind. Eng. Chem. Prod. Res. Dev. 1983, 22, 303-307 303 Reactivity of Kel-F Polymers with Organolithium and Organomagnesium Compounds Neil D. Danlelson,' Rlchard 1. Taylor, Jeffrey A. Huth, Rlchard W. Slerglej, James 0. Galloway, and Joseph B. Paperman ...
Journal of Liquid Chromatography & Related Technologies, 2007
Alkylammonium formate (AAF) ionic liquids, RNH3 [HCO2 ], R=C2H5, C3H7, or C4H9, are prepared in h... more Alkylammonium formate (AAF) ionic liquids, RNH3 [HCO2 ], R=C2H5, C3H7, or C4H9, are prepared in high yield and purity by slowly reacting an alkylamine and formic acid in an ice bath under N2. UV spectra of undiluted ethylammonium formate (EAF), n‐propylammonium formate (PAF), n‐butylammonium formate (BAF) show no appreciable background absorbance down to about 250 nm, 270 nm, and 295 nm, respectively. Physical
A simple and green ultra-high-performance micellar liquid chromatography (MLC) method was develop... more A simple and green ultra-high-performance micellar liquid chromatography (MLC) method was developed here, comparing Tween 20 and Tween 40 for the first time as the only mobile phase modifiers with a C18 column. Its application to the separation of nine hydroxycinnamic acid (HCA) derivatives (cinnamic, caffeic, ferulic, sinapic, o-, m-, p-coumaric, 3,4-dihydroxyhydrocinnamic, and chlorogenic acids) was made, due to their importance as antioxidants in a variety of natural beverages such as wine and coffee. The optimal conditions of 45 °C temperature (T), 1% surfactant in the mobile phase, and pH control with 2.5 mM sulfuric acid were determined and used to elucidate the analytical figures of merit. Although the effect of these conditions was insignificant between the two surfactants, the nine-component HCA mixture was separated faster—in about 15 min—and with less peak tailing using Tween 20 than with Tween 40. The linearity of the Van’t Hoff (lnk versus 1/T) plots was evident for Twe...
Abstract The use of polychlorotrifluoroethylene (PCTFE) particles packed in 5–10 cm × 0.4 cm ID c... more Abstract The use of polychlorotrifluoroethylene (PCTFE) particles packed in 5–10 cm × 0.4 cm ID columns for the immobilization of enzymes by hydrophobic adsorption is investigated. Enzyme binding capacity of PCTFE is about 0.2 mg/gm of polymer. PCTFE-immobilized lactate dehydrogenase, alcohol dehydrogenase, and urease-glutamate dehydrogenase are demonstrated to be useful for the determinations of pyruvate, ethanol, and urea, respectively. Immobilized enzyme lifetimes are generally about 1–2 months.
The photochemical activities of six sulfa compounds [sulfacetamide (CET), sulfadiazine (DIA), sul... more The photochemical activities of six sulfa compounds [sulfacetamide (CET), sulfadiazine (DIA), sulfaguanidine (GUA), sulfamerazine (MER), sulfamethoxazole (SMX), and sulfamethizole (MET)] under different experimental conditions such as photolysis time, ...
Hrc-journal of High Resolution Chromatography, May 1, 1992
Page 1. Short Communications separations are performed between 60 and 140 "C, the te... more Page 1. Short Communications separations are performed between 60 and 140 "C, the tempera-ture limitations of these connectors do not seem too restrictive. Deactivation of the quartz couplings was essential for obtaining ...
Journal of Chromatography B: Biomedical Sciences and Applications, Nov 1, 1980
A direct assay for creatine kinase (CK) activity was developed based on the separation and quanti... more A direct assay for creatine kinase (CK) activity was developed based on the separation and quantitation of adenosine triphosphate (ATP) by high-performance liquid chromatography. The total incubation time is 13 min and the elution time for ATP is 16 min. Using lyophilized CK as the sample, a sensitivity in the range of 8 U/l (units/liter) was obtained. The method presented also has clinical significance in that CK levels in serum can easily be determined with minimal sample preparation. Using serum samples from a healthy patient and a heart attack victim, activities of 26.6 U/l and 609.0 U/l, respectively, were obtained. Because of the direct measurement of ATP, this method eliminates the coupled reactions encountered in the common spectrophotometric and colorimetric methods of analysis resulting in a simpler and inexpensive assay.
Industrial & Engineering Chemistry Product Research and Development, Jun 1, 1983
Page 1. Ind. Eng. Chem. Prod. Res. Dev. 1983, 22, 303-307 303 Reactivity of Kel-F Polymers with O... more Page 1. Ind. Eng. Chem. Prod. Res. Dev. 1983, 22, 303-307 303 Reactivity of Kel-F Polymers with Organolithium and Organomagnesium Compounds Neil D. Danlelson,' Rlchard 1. Taylor, Jeffrey A. Huth, Rlchard W. Slerglej, James 0. Galloway, and Joseph B. Paperman ...
Journal of Liquid Chromatography & Related Technologies, 2007
Alkylammonium formate (AAF) ionic liquids, RNH3 [HCO2 ], R=C2H5, C3H7, or C4H9, are prepared in h... more Alkylammonium formate (AAF) ionic liquids, RNH3 [HCO2 ], R=C2H5, C3H7, or C4H9, are prepared in high yield and purity by slowly reacting an alkylamine and formic acid in an ice bath under N2. UV spectra of undiluted ethylammonium formate (EAF), n‐propylammonium formate (PAF), n‐butylammonium formate (BAF) show no appreciable background absorbance down to about 250 nm, 270 nm, and 295 nm, respectively. Physical
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