High Performance Liquid Chromatographic Analysis of Curcuminoids and Their Photo-oxidative Decomposition Compounds in Curcuma Longa L

Abstract

Photochemical oxidation of curcuminoids such as curcumin, bis-demethoxycurcumin and demethoxycurcumin in dry powder of Curcuma longa L. (zingiberaceae) root and in ethanolic and methanolic extract has been studied. Whatman PartiSphere-5 NH₂ and Whatman Partisphere-5 WCX columns were used to analyze curcuminoids and their degradation products. The curcuminoids were found to be more stable in the dry powder of Curcuma longa L. root than in ethanolic and methanolic extracts. Vanillin, p-hydroxybenzaldehyde, ferulic aldehyde, p-hydroxybenzoic acid, vanillic acid and ferulic acid were identified as the oxidation products.     

pitfalls in Using Filter Paper Disks as Standard Supports In X-Ray Fluorescence Spectrometry

Abstract

Standard solutions of dimethylarsinic acid in water and methanol are deposited on Whatman No. 1 and No. 114 filter papers. The arsenic content is measured by X-ray fluorescence spectrometry. The observed specific count depends on the nature of solvents, the volume of spotting solutions, the method of spotting and the type of filter papers.     

Liquid Chromatography Analysis of Hippuric Acid

Abstract

Hippuric acid analysis by TLC is demonstrated. Both normal silica and reverse phase C¹⁸ TLC plates are used with fluorescent quenching to visualize the hippuric acid. Urine samples may be spotted directly or extracted with CHCl₃ to concentrate the hippurate. Tissues may be analyzed in this same manner. Aluminum backed Merck TLC plates give best normal phase separation of tissue extracts and Whatman C¹⁸ give best reverse phase separation of tissue extracts. A Kontes scanner may be used to directly analyze TLC plates or the bands may be removed and analyzed by ultraviolet spectroscopy. Confirmation may be done by mass spectrometry.     

The Paper Electrophoresis of Alkaloids with Strong Acids as Electrolytes

Abstract

Some alkaloids were studied by paper electrophoresis using strong acids (0.1 N and 0.5 N) as electrolyte. There are differences in the separations obtained depending on the acid. Perchloric acid and trichloroacetic acid gave the best separations.     

Determination of lead in atmospheric particulates by flameless atomic absorption spectrometry with a graphite tube

A procedure for the determination of atmospheric particulate lead by flameless atomic absorption spectrometry is described. Aerosols are collected on 10-cm Whatman 41 filters with high-volume pumps. The lead is removed from a one-eighth sector of the filter by two ultrasonic treatments in 0.1 M nitric acid for 10 and 5 min, respectively. Investigations, including comparison with samples pre-ashed at low temperature, indicated that the lead was completely recovered. Routinely 20-μ1 amounts of the solution are injected into a graphite tube and the % absorption at 283.3 nm is measured. The elements normally encountered in atmospheric aerosols do not interfere. The sensitivity for 24-h samples is 0.01 μg m^?3 of air. Sampling time can be reduced to a few minutes in urban air when a larger segment of the filter is used and a larger volume is injected. The reproducibility of the complete procedure is 3% for a typical lead concentration of 0.35 μg m^?3. The method was applied to short-period variations of the lead concentration in urban air.     

Determination of Lead in Dinnerware by an Ion Exchange Filter Paper ‐ X-Ray Fluorescence Method

Abstract

Lead leached from a variety of pottery dinnerware was determined by x-ray fluorescence after collecting and concentrating the lead on an ion exchange resin loaded filter paper disc. A 0.01 M HCl solution, to simulate acidic foodstuffs, used for the leaching was shown to have a leaching rate almost identical to that of white vinegar. The leaching rate increased with increasing temperature. The relative standard deviation for successive determinations of the same lead content was 1.8%, and the detection limit was 1.08 μg of total lead which corresponded to 0.0072 ppm when 150 ml of leaching solution was used.     

Chromatography Op Primary Aromatic Amines on Cellulose and Carboxymethylcellulose Papers

Abstract

The chromatography of a series of primary aromatic amines is studied on papers composed of pure cellulose and carboxy-methylcellulose with water, acetic acid and an acetate buffer as solvents. Migration data and possible separations are reported, and results are compared with those obtained on carboxymethylcellulose thin layers.     

The Paper Chromatography of Metal Ions in Butanol-HCLO4 Mixtures

Abstract

Rf values are reported for 37 cations and 5 anions in several butanol-perchloric acid mixtures, ranging from 0.1 to 2.5 N perchloric acid. A few of the metal ions and all of the anions were found to have high Hf values.     

Ion-Exchange Chromatographic Separation of Anions on Hydrated Bismuth Oxide Impregnated Papers

Abstract

A comparative study of the chromatographic behaviour of anions, iodide, sulphide, phosphate, arsenate, arsenite, vanadate, chroraate, dichromate, thiosulphate, thiocyanate, ferricyanide and ferrocyanide on papers impregnated with hydrated bismuth oxide and untreated Whatman no, 1 papers has been made by employing identical aqueous, non-aqueous and mixed solvent systems. Sharp and compact spots were obtained with impregnated papers whereas the opposite applied to plain papers. Various analytically important binary and ternary separations are reported.     

Colored Gift Wrapping Papers as a Potential Source of Toxic Metals

Abstract

Sanitary land fills are the alternate to waste incineration in New Jersey. While industrial waste disposal is controlled, few restrictions apply to the disposal of domestic solid waste. Among the materials of concern from domestic sources are colored gift wrapping papers. Cadmium, chromium, copper, iron, manganese, molybdenum, nickel, lead and zinc were determined in some dozen and a half samples of gift wrapping paper by atomic absorption spectrometry after wet ashing and after simulated leaching. High levels of lead and chromium were found in many of the papers. The leachates showed correspondingly high levels of lead.     

Semi-Preparative High Performance Liquid Chromatographic Separation of Carbon-14 Labeled Avermectin B1a from a Mixture of Avermectins

Abstract

A semi-preparative high performance liquid chromatographic method has been developed to separate carbon-14 labeled avermectin B_1a from a fermentation mixture of carbon-14 labeled avermectins, i. e., avermectins A₁a, A₁b, A₂a, A₂b, B₁a, B₁b, B₂a, and B₂b. Two HPLC systems were employed for the separation: I. A Whatman M20, Partisil 10, normal phase column and a solvent system of 10% ethanol in isooctane (v/v), and II. A Whatman M20, Partisil 10, ODS-3, reverse phase column and a solvent system of acetonitrile/methanol/water (56:18:26, v/v/v); the flow rate was 18 ml/ min. Avermectin separations were monitored using ultraviolet detection (254 nm). Further analyses of avermectin B₁a were done using analytical HPLC and TLC/radioassay to check compound purity and identity.     

Studies on Batch Sorption Methodologies: Eu Sorption onto Kivetty Granite

Six different methodological features of the batch sorption experiment were investigated using ¹⁵²Eu, Kivetty granite, saline water with initial pH of 8.5, 9 and 10, [Eu]tot=5·10^-7M, S:L = 1:20, pre-washing of granite, occasional shaking, centrifugation, wall sorption correction with separate tubes. This gave final Rd= 8.3±2.1, 7.3±2.6 and 8.6±3.7m³/kg at 6 months for each pH, respectively. Then [Eu]tot and S:L were varied, filtration was compared with centrifugation, separate tubes for wall sorption was compared with wall desorption, pre-washing of granite was compared with no washing and two shaking methods were compared. Two of the investigated methodological features gave too large apparent Rd due to: 1) filter sorption, and 2) low radiotracer concentration, leading to detection problems.     

Microwave Assisted Synthesis of 2-(4-Methoxylbenzoylamido)-5-Aryloxymethyl-1,3,4-Thiadiazoles

4-Methoxylbenzoyl chloride reacting with ammonium thiocyanate and aryloxyacetic acid hydrazides under phase transfer catalysis at room temperature gives 1-aryloxyacetyl-4-(4-methoxylbenzoyl)-thiosemicarbazides (Ia-m). Compounds Ia-m together with glacial acetic acid on exposure to microwave irradiation lead to the formation of 2-(4-methoxylbenzoylamido)-5-aryloxymethyl-1,3,4-thiadiazoles (IIa-m) in excellent yields.     

Synthesis of 1-p-Methoxyphenyl and 1-p-Methoxyphenyl-4-methylbicyclo-[2.2.1]heptan-7-one. The Oxidation of 7-Hydroxy-1-p-methoxyphenyl-4-methylbicyclo[2.2.1]heptan-7-carboxylic Acid with Lead Tetraacetate

A simple synthetic route to 1-p-methoxyphenyl and 1-p-methoxyphenyl-4-methylbicyclo [2.2.1]heptan-7-one 6b,a has been developed through benzilic acid rearrangement of the bicyclo[2.2.1]octandiones 2b,a. The oxidation of 7-hydroxy-1-p-methoxyphenyl-4-methylbicyclo[2.2.1]heptan-7-carboxylic acid 3a with lead tetraacetate gives the carbolactone 7a which is also formed by the reaction of the ketone 6a with m-chloroperbenzoic acid.     

Electrochemical Study of Lead Complexes With Folic Acid and Its Related Compounds

Abstract

The equilibria existing in unbuffered aqueous medium between lead ions and folic acid or its related derivatives (pterin, pterin-6-carboxylic acid, pteroic acid and glutamic acid) have been investigated using differential pulse polarography. All these compounds, except pterin-6-carboxylic acid and glutamic acid, exhibit three consecutive complexes with increasing ligand concen-     

The Effect of Surfactants On the Chromatographic Separation of Phenols On Papers Impregnated With Hydrated Cerium Oxide

Abstract

The effect of surfactants on the chromatographic behaviour of 16 phenols of different nature have been observed on Whatman No 2 paper strips impregnated with hydrated cerium oxide. the movement of phenolic spots was observed in various mobile phase solvents with or without 4m ML^?1 8m ML^?1 and 12m ML^?1 sodium dodecyl sulphate (SDS). It is observed that the use of micellar mobile phase systems, which improve the selectivity and compactness of the spots, offered significant advantages over traditional solvents. On the basis of appreciable differences in the af values of phenols a variety of bioanalytically important binary and ternary separations were achieved without using separate detecting reagents, as most of the phenols appear as coloured spots with cerium oxide papers.     

The Use of High Pressure Liquid Chromatography for the Identification and Preparation of Pigments Concerned in Photosynthesis

Abstract

The chlorophylls and carotenoids present in preparations from chloroplasts of marine algae can be extracted and separated by high pressure liquid chromatography (H.P.L.C.). The reverse-phase columns; Partisil 10 ODS (Whatman), μ Bondapak C18 and μ Bondapak CN (Waters Associates) gave good separation of the different pigments. Addition of the ion-pairing agent tetrabutylamnonium phosphate to the methanol/water solvents gave improved separations with complex mixtures and identification was facilitated by examination of the column eluant at 440nm where a ll the pigments absorbed and at 650nm where only chlorophylls absorbed. The method allowed the isolation of individual pigments for further study.     

Determination of tin in atmospheric particulate matter by hydride generation and atomic absorption spectrometry

A procedure is described for the determination of tin in atmospheric particulate matter collected on Whatman 41 cellulose filters. The samples are decomposed with sulfuric acid and nitric acid, followed by hydrofluoric acid to dissolve residual silicates. The analytical parameters for the hydride generation and the subsequent atomic absorption spectrometric measurements are optimized. Severe memory effects encountered with an automatic generator system are avoided when a manual apparatus is used. The precision of the entire method is within 10%. The detection limit is 0.20 ng m^?3 tin if 500 m³ of air is filtered. The concentrations found in residential and industrial areas varied between 1.8 and 47.5 ng m^?3.     

Analysis of Biological Tissues for Selenium by Thin Layer Chromatography

Abstract

Selenium is oxidized by the method of Poole¹ as modified by Stahr, et al⁴ to free it from matrix encumbrances. It is reduced by HC1 dissolution and complexed with DAN (Diaminonapthalene) then extracted into cyclohexane and analyzed by TLC (reverse phase Whatman high performance plates) thin layer chromatography densitometry. TLC allows observation of 0.1 ng of the selenium (piazselenole) complex. Separation of the Se containing complex allows elimination of other potentially interfering fluorescent compounds. 100% recoveries of Se⁷⁵ (radiolabelled) are achieved through the digest step and 85–90% are achieved through the complete test. Radioautography shows only the gold piazselenole spot contains selenium. Agreement with Bureau of Standards results on freeze dried liver is 100% ± 2%.     

NEW PROTOCOL FOR CONVERTING ALCOHOLS INTO AMINES

The reactions between diethyl N-(t-butoxycarbonyl)phosphoramidate 1, diisopropyl azodicarboxylate (DIAD), triphenylphosphine (TPP) and primary or secondary alcohols lead to the corresponding diethyl N-alkyl-N-(t-butoxycarbonyl) phosphoramidates 2a-o. Deprotection of crude 2 by refluxing with p-toluenesulfonic acid monohydrate in ethanol affords ammonium tosylates 3a-o in moderate to good overall yields. The N-alkylation of 1 proceeds stereoselectively with complete inversion of the configuration of the alkyl group.