Thin layer chromatographic fingerprint of Rhizomata of Coptis spp

This paper introduces the use of optimized solvent system with twice-ascending-development in twin trough chamber on TLC silica gel plate for the separation of protoberberine-type alkaloids contained in Rhizomata of Coptis spp. Nine to eleven spots including the main and the 'minor' alkaloids in the samples can be observed on the chromatograms obtained under controlled conditions. The fluorescence and UV-absorption TLC scanning profile can serve as fingerprint for the analysis of commercial samples of Rhizomata of Coptis spp.     

Thin layer chromatographic estimation of available lysine in dried milk powder

A rapid method for the estimation of available lysine in dried milk powder has been developed. Samples were treated with 2,4,6-trinitrobenzene sulfonic acid and then hydrolyzed with 6N HCl. The hydrolysate was purified and subjected to ascending thin layer chromatography to isolate xi-trinitophenyl lysine in pure form. The color was read at 346 nm in a specitrophotometer.     

Automated determination of protein-nitrogen in cereals and grains

This paper presents the design, performance, and operational characteristics of a new direct reading instrument for determining nitrogen in cereal and grain. Precision, accuracy, range, speed, ease of operation, sensitivity, sample size, and flexibility of the instrument are presented. Results on various cereals and grains are presented and compared with those obtained by the Kjeldahl technique. The apparatus is the result of research for a rapid method for determining nitrogen in organic material. The instrument uses a combination of a unique high temperature sample oxidation, a sampling valve for separating combustion products, and thermal conductivity detection for the liberated nitrogen in a helium carrier gas.     

Determination of phosphine residues in whole grains and soybeans by ion chromatography via conversion to phosphate

An ion chromatographic (IC) method was developed for determining phosphine (PH3) in whole grains (barley, corn, oats, rice, rye, and wheat) and soybeans. The method converts phosphine to phosphate (i.e., orthophosphate) and isolates the phosphate by IC with eluent-suppressed conductivity detection. Recoveries of unbound phosphine by the method were similar to those obtained by an established colorimetric method for 7 different products fortified at 3 levels. Mean recoveries were low (i.e., 30-60%) and varied with product type and level of fortification. Recoveries of PH3 from previously fumigated products fortified with aluminum phosphide ranged from 19.0% for barley fortified at 0.734 ppm to 88.3% for corn fortified at 1.691 ppm. Precision data from 3 products based on replicate analyses (n = 4 or 5) gave relative standard deviations of 1.78-4.66% for mean laboratory-fumigated PH3 levels of 0.679-1.309 ppm. Estimated limits of detection (LOD) and quantitation (LOQ) for PH3 were 0.010 microgram/g (10 ppb) and 0.0275 microgram/g (27.5 ppb) at signal-to-noise ratios (S/N) of 4:1 and 10:1, respectively. These values were also determined for a nonchemically suppressed IC system with LOD of 0.02 microgram/g (20 ppb) and LOQ of 0.055 microgram/g (55 ppb) at S/N of 4:1 and 10:1, respectively. Phosphate response was linear over the concentration range equivalent to 0.30-10.0 micrograms P/mL, with a mean correlation coefficient of 0.9988 based on replicate standard curves. The relationship of product composition to recovery from various products was also examined.     

Gas-liquid chromatographic determination of alachlor (2-chloro-2', 6'-diethyl-N-(methoxymethyl)-acetanilide) herbicide residues in corn and soybeans

A method has been developed for the extraction and determination of alachlor (2-chloro-2',6'-diethyl-N- (methoxymethyl)-acetanilide) residues in green corn and soybeans. Residues are extracted with acetonitrile and cleaned up on a Florisil column. The methylene chloride extract is sufficiently clean for electron capture gas-liquid chromatographic analysis and for verification by thin layer chromatography. Average recoveries of spiked samples (0.2 ppm) were 69 and 82% for corn and soybeans, respectively. This procedure could be useful for the detection of the parent compound in these crops soon after field application, but it does not detect metabolites.     

Liquid chromatographic determination of ivermectin in feed

An analytical method for determining ivermectin in feed at 0.50-3 ppm is presented. The method is based on liquid chromatographic measurement after sample preparation by adsorption chromatography on alumina and solid-phase extraction. Two complete, final, finished medicated feeds and the corresponding control feeds used in their preparation were analyzed. Recoveries from feeds fortified at 50-150% of the 2 ppm ivermectin use concentration also were determined. Mean recoveries from replicate analyses ranged from 90 to 100%, and coefficients of variation (CVs) were less than 4.5%. No significant interferences were found in control feeds. The pooled distribution of individual analytical results (n = 100) gave a mean recovery of 100%, a recovery range of 90-111%, and an overall CV of 5.5%. Resolution of the total variance into its 2 components gave a within-laboratory CV of 4.1% and a between-laboratory CV of 3.4%. There was no significant difference in recoveries among laboratories, days, concentrations, and feed base or between fortified and medicated feeds (P > 0.2).     

Effects of different cereal grains in diets for laying hens on production parameters and liver fat content

Two experiments were conducted with White Leghorn laying hens to study the effects of different cereal grains on production criteria and liver fat content. The results of Experiment 1, in which pullets 21 weeks of age were used for a period of 22 weeks indicated that Gaines wheat or triticale (Trailblazer) were equal to corn in supporting egg production, egg weight and body weight, with comparable feed consumption. Henry wheat(a hard red winter class) was slightly, yet significantly (P less than 0.05) inferior to corn for the above criteria. No significant differences were observed among four treatments in wet liver weight and liver fat content. Hens fed the corn diet had significantly (P less than 0.05) lower carcass fat followed by the hens fed triticale in comparison with those fed Gaines or Henyry wheat. Mortality was very low and not related to dietary treatments. Neither dietary fat nor energy content was related to fat content of liver and carcass of the hens. Body weight and liver fat content were not closely related to each other. Wet liver weight was the only significantly (P less than 0.05) related factor to liver fat content. In the second experiment, in which hens 33 weeks of age were used for an experimental period of 20 weeks, opaque-2 corn was slightly superior to normal corn and triticale was comparable to normal corn in supporting egg production and egg weight. Supplementation of the diets containing the two corns and triticale with lysine failed to improve egg production and egg weight. Hens fed the diets containing either normal corn or opaque-2 corn as the only grain in the diet had significantly (P less than 0.05) higher liver fat content in comparison with hens fed the diet containing triticale as the only grain. Mortality, however, was much higher among hens fed triticale-containing diets in comparison with groups fed corn-containing diets in spite of the fact that they had significantly lower liver fat content. Regardless of dietary treatments or grains used, the hens that died were diagnosed to have fatty liver hemorrhagic syndrome. Dietary fat content was postively and significantly (P less than 0.05) related to liver fat content. Dietary energy or body weight was not closely related to liver content. Liver fat content and mortality were negatively related to each other. The higher for content did not adversely affect laying performance.     

Effect of the protein matrix on the digestion of cereal grains by ruminal microorganisms

Experiments were conducted to investigate the role of the protein matrix in the digestion of barley and corn by ruminal microorganisms. Grains, ground and collected on sieves as two particle fractions .25 to .89 mm (small particles) and 2.00 to 3.00 mm (large particles), as well as isolated barley and corn starch granules, were incubated with ruminal inocula. For both grains, digestion of starch in small particles was greater (P < .001) than that of large particles. At 16 and 24 h starch digestion was greater (P < .01) in barley than in corn, for small and large particles. Digestion of barley starch granules did not differ (P > .05) from that of corn starch granules at any incubation time. A 4-h preincubation of small-particle corn and barley with protease increased (P < .001) microbial digestion of starch in corn at 16 h but did not affect digestion of barley. When four ruminally cannulated steers were fed diets containing 80% barley, corn, or wheat or 100% alfalfa hay in a 4 x 4 Latin square experiment, amylolytic activity of ruminal inoculum was higher for steers fed grains than for those fed alfalfa. However, when standardized for total viable counts of bacteria, ruminal amylolytic activity did not differ (P > .05) among diet treatments, but proteolytic activity of ruminal inoculum for steers fed alfalfa was higher (P < .01) than that for steers fed cereal grains. Activity of serine proteases in ruminal inoculum was higher (P < .05) for steers fed alfalfa than for steers fed grains.(ABSTRACT TRUNCATED AT 250 WORDS)     

Gas chromatographic determination of hydrazoic acid

A gas chromatographic procedure was developed for the determination of hydrazoic acid. Two possible columns were evaluated. The limits of detectability were 1.5 ng, or approximately 0.05%, in aqueous solution (w/v) and 2 mg per liter in air.     

Gas chromatographic determination of acenocoumarin in human plasma

A method based on solvent extraction, formation of a fluorinated derivative and quantitation by gas-liquid chromatography with electron-capture detection has been developed for the determination of acenocoumarin in plasma. The specificity and sensitivity of the procedure appear to be satisfactory for drug level measurements in human plasma. Its relative simplicity permits its use in routine analysis.     

Gas-liquid chromatographic determination of chloramphenicol in agricultural crops

A method is presented for the gas-liquid chromatographic determination of chloramphenicol in agricultural crops. Chloramphenicol is extracted with ethyl acetate, cleaned up by silicic acid column chromatography, acetylated with acetic anhydride and pyridine, and then measured by gas-liquid chromatography with electron capture detection. Two stationary phases, DEGS + phosphoric acid and Reoplex 400, were used. The sensitivity was ca 8 ng (40% full scale deflection). The efficicency of the analytical method was evaluated by analyzing crops fortified with chloramphenicol. The average recovery ranged from 72% in unpolished rice to 86% in Chinese radishes.     

Gas-liquid chromatographic determination of total inorganic iodine in milk

Total inorganic iodine in milk is determined by conversion to iodobutanone, which is quantitated by gas-liquid chromatography and electron capture detection. As little as 10 microgram/L can be determined. The thyroid-active iodine content of milk can be determined rapidly with a relative standard deviation of 1.9%. Average recoveries for added iodide and iodine were 95.5 and 94.6%, respectively.     

High-pressure liquid chromatographic determination of acetaminophen in biological fluids

A method for the rapid estimation of free acetaminophen in biological fluids is described. The assay involves either extraction and high-pressure liquid chromatographic analysis on a 10-mum particle-size silica gel column, using a mobile phase of 10% chloroform in tetrahydrofuran. The procedure was used to determine acetaminophen levels in urine from two healthy volunteers who ingested 650 mg of 14C-acetaminophen (20 muCi), and the accuracy of the method was compared with the carbon-14 determination. The limit of detectability for acetaminophen is 1 mug/ml.     

High-pressure liquid chromatographic determination of thiothixene in pharmaceutical formulations

A method was developed for the quantitative determination of thiothixene in pharmaceutical formulations by high-pressure liquid chromatography after dissolution of the sample in methanol.     

Liquid chromatographic determination of safrole in sassafras-derived herbal products

A liquid chromatographic (LC) method was developed for determining safrole in herbal products derived from sassafras (Sassafras albidum), as well as related compounds such as isosafrole and dihydrosafrole. The procedure involves solvent extraction and isolation of analyte by reversed-phase LC with UV detection at 235 nm. Safrole is resolved from related compounds and other sample constituents including thymol, a component of thyme. A linear concentration range of 0.003-0.200 mg/mL was obtained for safrole, isosafrole, and dihydrosafrole. Limits of detection (LOD) and quantitation (LOQ) were e0.0015 and 0.0051 micrograms/mL for safrole, 0.0018 and 0.0061 micrograms/mL for isosafrole, and 0.0038 and 0.0125 micrograms/mL for dihydrosafrole, respectively. Intraday relative standard deviations (RSDs) for safrole (n = 5) from various samples ranged from 1.30 to 5.39% at analyte levels of 0.01-1.5%. Safrole contents of 26 samples including root bark powder, leaves, oils, tea concentrate, herbal extract tinctures, and herbal powder capsules ranged from < LOD for most leaf samples to 92.4% for an oil. Recoveries of safrole from fortified samples ranged from 83.6% for an oil to 117.2% for a tincture preparation. Safrole contents of 0.09-4.66 mg/cup were found for brewed teas prepared from sassafras root bark powders and tinctures.     

High-performance liquid chromatographic determination of tramadol in human plasma

Tramadol has been determined in human plasma samples using a sensitive high-performance liquid chromatographic method. The plasma samples were extracted with tert.-butylmethyl ether in one-step liquid-liquid extraction (recovery 86%) and analyses of the extracts were performed on reversed-phase silica gel using ion-pair chromatography (verapamil as an internal standard) and fluorescence detection. The method was applied to the determination of tramadol levels in twelve healthy volunteers after oral administration of 100 mg of tramadol in capsules of Protradon and Tramal.