ABSTRACT
Size-exclusion chromatography (SEC) and chemiluminescent nitrogen detection (CLND) were used to estimate the molecular-mass distribution of food-grade protein hydrolyzates. Simultaneous CLND and UV (214 nm) detection is demonstrated for analytical SEC of an experimental casein hydrolyzate. In order to validate the estimated average M(r) values derived from the SEC column data, a preparative SEC separation of an extensive casein hydrolyzate was pursued. Fractions were collected on a time basis and analyzed by time-of-flight (TOF) mass spectrometry. A plot of TOF M(r) vs. SEC M(r) indicated that the peptides below M(r) of 1200 were eluted as estimated by the calibrated preparative SEC column. This paper demonstrates the power of using a dual CLND and UV detection system for analytical SEC analysis of protein hydrolyzates with a calibrated column.
Subject(s)
Chromatography, Gel , Food Analysis , Luminescent Measurements , Nitrogen/analysis , Proteins/chemistry , Caseins/chemistry , Hydrolysis , Molecular WeightABSTRACT
Reversed phase high-performance liquid chromatography with chemiluminescent nitrogen detection (HPLC-CLND) was used for the quantitative analysis of peptides manufactured by solid-phase peptide synthesis. CLND provided quantitative information regarding the nitrogen distribution of peptide samples following HPLC separation. This technique permits the universal quantitation of the "peptide content" of synthetic peptides in an on-line mode without pre- or post-column derivatization and free of interference from non-nitrogen-containing UV chromophores. This paper will show the utility of this novel technique in measuring the peptide content of crude synthetic proinsulin chain C peptide. A mixture of five reference peptides was analyzed to show the homogeneity of the CLND response and used to determine peptide content. Application for the purified product is also discussed. The detection profiles were acquired in parallel with a UV detector.
Subject(s)
Nitrogen/analysis , Peptides/analysis , Angiotensin II/chemistry , C-Peptide/chemistry , Chromatography, High Pressure Liquid , Enkephalins/chemistry , Luminescent Measurements , Peptides/chemical synthesis , Peptides/chemistry , Peptides/isolation & purificationSubject(s)
Infant Food/analysis , Vitamin K 1/analysis , False Negative Reactions , Humans , Infant , MethodsSubject(s)
Infant Food/analysis , Oils/analysis , Vitamin K 1/analysis , Animals , Biological Assay , Chickens , Chromatography , Food Analysis , Humans , Hypoprothrombinemias/etiology , Infant , Methods , Milk/analysisSubject(s)
Chromatography , Infant Food/analysis , Vitamin D/analysis , Animals , Chromatography, Thin Layer , Humans , Infant, Newborn , Methods , Milk/analysis , Glycine max/analysisABSTRACT
The fecal extraction procedure described by Evrard and Janssen (1) was inadequate for the complete extraction of conjugated bile acids from feces containing the bile acid sequestrant, cholestyramine. As judged by gas-liquid chromatographic analysis, substitution of 0.5 n HCl in absolute ethanol for glacial acetic acid allowed for complete recovery (98-104%) of three different conjugated bile salts in the presence of the resin.