mL Of Solvent Research Articles

Effects of AFB 1 embryonic exposure on chicken mononuclear phagocytic cell functions

Effects of embryonic exposure to aflatoxin-B 1 (AFB 1) on the postnatal development of chicken mononuclear phagocytic system function was examined. Single exposure of 6-d chick embryos to 0.1, 0.5, and 1 μg AFB 1 in 10 μL acetone was employed. Control embryos received 10 μl solvent and sham-treated controls included embryos with a hole in the egg shell with no compound added. Aflatoxin B 1 exposure caused a dose-related increase in embryonic mortality. After hatch, no differences were observed in body weight gain among treatment groups. The incidence of circulating thrombocytes was reduced in chicks exposed to the highest AFB 1 dose with enhancement in monocyte and lymphocyte cell populations. Birds exposed to 1 μg AFB 1 recruited fewer macrophages in the peritoneal cavity after i.p. Sephadex elicitation along with reduced substrate adherence potential of peritoneal exudate cells. Similarly, macrophages from 0.5 and 1 μg AFB 1-treated birds had depressed phagocytic potential. These results suggest that long-term immune depression of macrophage-mediated functions can occur following embryonic exposure to AFB 1.

A prospective randomised trial of radiation with or without oral and intravesical misonidazole for bladder cancer

Patients with T2 grade 3 and T3 bladder cancer were randomised to be treated with radiation alone (NO MISO) or with radiation and misonidazole (PLUS MISO). Patients in both groups initially received 40 Gy in 2 Gy fractions (5/week). Patients in the NO MISO arm received a further 20 Gy in 2 Gy fractions (5/week). Patients in the PLUS MISO arm received a further 12 Gy in 6 Gy fractions (1/week). MISO was administered orally (3.0 g m-2) and intravesically (1.0 g in 35 ml of solvent) 4 h and 2 h respectively prior to each fraction of 6 Gy. Fifty-eight patients were randomized of whom 53 are evaluable. There is a minimum follow-up of 5 years in the surviving patients. In the NO MISO and PLUS MISO arms, the complete response rate at cystoscopy at 6 months was 63% and 69%, the 5-year survival rate was 41% and 48% and the 5-year local control rate with bladder preservation was 46% and 36% respectively (censored for death from metastases while locally clear). These differences are not statistically significant. Two patients had grade 3 RTOG late bowel complications. Both patients were in the PLUS MISO arm, had undergone salvage cystectomy and subsequently required colostomies for bowel obstruction for a 5-year late complication rate (RTOG grade 3) of 9%. In addition, two patients in the PLUS MISO arm developed wound sepsis post cystectomy. We were not able to demonstrate improved results from the use of oral and intravesical MISO in this study. The number of patients entered are relatively low and large differences would have been required to be detected with a power of 0.80. The use of an unconventional radiation fractionation schedule may have resulted in increased bowel morbidity in patients in the PLUS MISO arm who subsequently underwent cystectomy.

Morphine-induced inhibition of ovulation in normally cycling rats: Neural site of action

Intracerebral injection of morphine ( 3 μg 0.2 μl of solvent) on the day of proestrus at 1200 hr bilaterally in the medial preoptic area (mPOA) and median eminence-arcuate (ME-ARC) region inhibited ovulation in the cycling female rats. The morphine antagonist, lethidrone ( 2 μg 0.2 μl of solvent) when injected in the mPOA and ME-ARC region followed by intraperitoneal morphine ( 3 mg 100 g body weight) administration, was found to reverse the ovulation blocking action of this opiate. Implantation sites at which morphine was effective in blocking ovulation were restricted to a narrow medial band encompassing the mPOA and ME-ARC region. Our data are consistent with the view that the endogenous opioid peptides in mPOA and ME-ARC region of the hypothalamus may be involved in the physiological regulation of the central neural events which lead to ovulation in the rat.

Nickel catalysed electrosynthesis of anti-inflammatory agents. Part I ? Synthesis of aryl-2 propionic acids, under galvanostatic conditions

Aryl-2 propionic acids such as fenoprofen and ibuprofen, which are anti-inflammatory agents, are synthesized by electrolysing a solution of ArCH(CH3)Cl in the presence of carbon dioxide and a nickel catalyst. The electrolyses are carried out galvanostatically in an undivided cell at a large scale of 50 mmol in 100 ml of solvent (e.g. tetramethylurea). Conversion rates close to 80% and chemical yields up to 85% are achieved. Electrolyses can be performed without catalyst.

High-resolution/higher-order derivative spectrophotometry for identification and estimation of synthetic organic pigments in artists' paints

Twenty-two pigments commonly used in artists' paints were investigated by recording the fourth-derivative (d 4) ultraviolet-visible spectra. Dimethyl sulphoxide was used as a universal solvent. It was possible to distinguish pigments which were chemically very similar and of the same colour, and to quantify the components of binary mixtures without separation by using side-peak-side ratio computations. Acrylic or oil media had no influence on the derivative spectra. For mixtures of more than two components, the pigments were separated by thin-layer chromatography and the d 4-spectra were recorded directly from the developed spots; 10 ng of each pigment in 5 μl of solvent was enough for the analysis.

Loop‐type interface for concurrent solvent evaporation in coupled HPLC‐GC. Analysis of raspberry ketone in a raspberry sauce as an example

AbstractPresently, two coupling techniques are used for directly introducing HPLC fractions into capillary GC: The retention gap technique (involving negligible or partially concurrent solvent evaporation) and fully concurrent solvent evaporation. While the former involves use of a conventional on‐column injector, it is now proposed that concurrent solvent evaporation technique be carried out using a switching valve with a built‐in sample loop. The technique is based on the concept that the carrier gas pushes the HPLC eluent into the GC capillary against its own vapor pressure, generated by a column temperature slightly exceeding the solvent boiling point at the carrier gas inlet pressure. Further improvement of the technique is achieved by flow regulation of the carrier gas (accelerated solvent evaporation) and backflushing of the sample valve (improved solvent peak shape).Concurrent solvent evaporation using the loop‐type interface is easy to handle, allows transfer of very large volumes of HPLC eluent (exceeding 1 ml), and renders solvent evaporation very efficient, allowing discharge of the vapors of 1 ml of solvent through the column within 5–10 min.

Sample collection, quantification, and identification in preparative anticircular planar chromatography

AbstractA preparative anticircular chromatography (PACH) device was constructed to elucidate different applications of separation problems as well as to compare different sample collection techniques in this particular PLC mode. An anticircular PC apparatus had to be established which allowed the utilization of 20 X 20 cm thin‐layer plates as well as sampling positioning at any given radius. Typical solvent migration times were 8–12 minutes and ca. 8–10 ml of solvent was needed for an entire 20 cm plate. It was shown that peak broadening effects due to diffusion during long migration could be avoided in the same way as for analytical anticircular PLC on 10 X 10 plates. On the other hand, longer migration distances allow increased resolution, in turn allowing higher sample loads, particularly in the case of trace compound enrichment. A full description of the apparatus is given, including the sampling device.Different sample collection techniques were tried and evaluated, including the through‐flow technique by on‐line center collection for plate washing as well as classical scraping‐off of interesting zones. Further evaluation of the method included quantification and evaluation of consistency by UV/VIS scanning after spot‐visualization. Several application examples are given to illustrate the efficiency of the preparative anticircular PLC‐system.

Rapid method for the analysis of trihalomethanes in water

A rapid and precise method for the analysis of trihalomethanes (THMs) in water is described. Samples are extracted with methyleyclohexane and analysed by gas chromatography using a short capillary column and electron-capture detection. THMs elute with baseline separation in 1.25 min, and detection limits of 1 μg/1 are readily achievable using 100-ml samples and 2 ml of solvent. Standards are prepared in the same way as samples by extraction of aqueous solutions to compensate for the relatively low extraction efficiencies which result from the low solvent to water ratio used. Ascorbic acid is a more effective sample preservative than sodium thiosulphate.

Bonded-phase extraction column isolation of organic compounds in groundwater at a hazardous waste site

A procedure for isolation of hazardous organic compounds from water for gas chromatography/mass spectrometry analysis is presented and applied to creosote- and pentachlorophenol-contaminated groundwater resulting from wood-treatment processes. This simple procedure involved passing a 50-100 mL sample through a bonded-phase extraction column, eluting the trapped organic compounds from the column with 2-4 mL of solvent, and evaporating the sample to 100 micro-L with a stream of dry nitrogen, after which the sample was ready for gas chromatography/mass spectrometry analysis. Representative compounds indicative of creosote contamination were used for recovery and precision studies from the cyclohexyl-bonded phase. Recovery of these compounds from n-octyl-, n-octadecyl-, cyclohexyl-, and phenyl-bonded phases was compared. The bonded phase that exhibited the best recovery and least bias toward acidic or basic compounds was the n-octadecyl phase. Detailed compound identification is given for compounds isolated from creosote- and pentrachlorophenol-contaminated groundwater using the cyclohexyl-bonded phase. 12 references, 1 figure, 4 tables.

A Solvent Extraction Technique for the Measurement of 222Rn at Ambient Air Concentrations

The high solubility of radon in cold organic solvents is exploited to extract radon directly from a sample air stream into a hexane-based liquid scintillation solution. Up to 10 l. of air is passed through 20 ml of solvent held at -78 degrees C in a bath of dry ice and acetone. The solvent is then transferred to an ordinary glass liquid scintillation vial that has been preloaded with 2 ml of concentrated fluors. A large number of samples can be prepared in a short time with minimal equipment, making it possible for field workers to conveniently collect numerous samples prior to returning to the laboratory. After allowing an interval of at least 3 hr after processing for radon daughter ingrowth, the vials are counted on an unmodified liquid scintillation system with a narrow window set around the radon and polonium alpha peaks. The large sample volume more than compensates for the relatively high alpha background of liquid scintillators. Relevant theoretical considerations and alternate sampling strategies are discussed.

A Simple and Economical Apparatus for Developing Thin-layer Chromatography Plates in the Anticircular Mode

Abstract An improved method for developing thin layer chromatography plates in the anticircular mode is described. The apparatus consists of two glass dishes arranged concentrically. The outer dish has a diameter of 98 mm × 15 mm deep, and the inner one a diameter of 92 mm × 13 mm deep. The inner dish rests on four small pieces of glass (5 × 5 × 2 mm). A paper wick, (16 mm wide × 1.5 mm thick) sits between the two dishes and transfers the solvent from the outer dish to the thin layer plates. The plate sits on the paper wick with the adsorbent facing down. To ensure an even solvent flow, the dishes are situated on a platform which has adjustable legs, and an horizontal level. Up to 50 samples can be analyzed on one 10 × 10 cm plate in 5 minutes. Less than 10 ml of solvent are needed.

Metrizamide in hysterosalpingography

We have recently had the opportunity of using metrizamide (Amipaque) during routine hysterosalpingography. It was used alternatively with Dimer-X in 44 patients. The metrizamide was dissolved using 4.7 ml of solvent with 3.75 g of metrizamide, giving an iodine concentration of 280 mg per ml—the same as Dimer-X.

Total parenteral nutrition (TPN) with complete nutritive mixtures: An artificial gut in cancer patients

Abstract A new technique in total parenteral nutrition (TPN), involving a deep vein indwelling catheter as a vascular access route, was applied to cancer patients in order to obtain a positive nitrogen balance. Various complete nutritive mixtures were administered; all were aseptic and apyrogenic; normonutrition mixtures contained 2000, 25000 and 3000 ml of solvent, while hyper‐nutrition mixtures contained 600 and 1200 ml of solvent. TPN (average duration 1.4 months) was used in 2122 cancer patients: 74.6% of patients underwent surgery, 15.8% had radiotherapy and 9.6% received only chemotherapy. A significant increase in the rate of operability of tumors was noted as a result of preoperative TPN, as well as an increase in the number of procedures involving extensive visceral resection. The results of a randomized study involving 81 patients with pelvic and/or abdominal irradiation revealed a significant increase in the degree to which radiotherapy was tolerated by the patients when TPN was administered du...

Micro-scale extractive alkylation procedure for the gas-chromatographic measurement of theophylline in serum and saliva, with use of a nitrogen detector.

In this 10-min gas-chromatographic assay for theophylline, a 25-microliter portion of serum or saliva sample, 100 microliter of extraction reagent, and 1.0 ml of solvent were mixed, the solvent separated and evaporated, and an aliquot of the reconstituted extract injected into the gas chromatograph. At a concentration of 11 mg/liter, within-run precision (CV) was 3.6% and run-to-run 2.9%. At 22 mg/liter, within-run precision was 2.8%. Concentration and instrument response are linearly related between 2 and 40 mg/liter. The limit of detection was 0.4 mg/liter. Results correlated well (r = 0.98) with those by another micro-scale gas-chromatographic procedure. Analytical recovery was estimated to exceed 90%, and no interferences from other xanthines or related drugs were observed.

4-Nitrophenol in 4-nitrophenyl phosphate, a substrate for alkaline phosphatase, as measured by paired-ion high-performance liquid chromatography.

We used paired-ion high-performance liquid chromatography to determine the 4-nitrophenol content of 4-nitrophenyl phosphate, a substrate for alkaline phosphatase analysis. This was done on a reversed-phase column with a mobile phase of methanol/water, 45/55 by vol, containing 3 ml of tetrabutylammonium phosphate reagent per 200 ml of solvent. At a flow rate of 1 ml/min, 4-nitrophenol was eluted at 9 min and monitored at 404 nm; 4-nitrophenyl phosphate was eluted at 5 min and could be monitored at 311 nm. Samples of 4-nitrophenyl phosphate obtained from several sources contained 0.3 to 7.8 mole of 4-nitrophenol per mole of 4-nitrophenyl phosphate.

Hydrothermal Extraction of Cr(VI) Ion from Chromite and Hydrothermal Innocentization of Chromite Slag

The hydrothermal oxidizing of chromite was suggested as the possible new wet metallurgical method of chromium. One gram of chromite sample and 5 ml of solvent was added into the micro-autoclave (12 ml of inner volume) with ball for stirring and induced 100 kg/cm' of 02 gas and then was heated in a revolving furnace at temperatures between 150 to 350°C. Cr (VI) ion in the eluted yellow solution was determined by colorimetric analysis. The extractio ratio of Cr(VI) ion from chromite was 70% under conditions of 350°C, 50 minutes. But at above this temperature, higher extraction ratio of Cr(VI) ion from chromite is expected. Besides, the chromite slag containing Cr(VI) ion of few percents was reduced perfectly under hydrothermal condition, at 350°C, for 80 minutes. And then, it was expected that the hydro- thermal process is appliciable as the harmless wet metallurgy of chromite.

A versatile twin-trough developing tank for thin-layer chromatography

A novel twin-trough developing tank is described. The bottom of the tank is separated into two troughs so that the amount of solvent can be reduced to approximately 20 ml, which is sufficient to saturate the tank and develop the chromatogram. After development, practically no solvent remains in the trough. A revision or change of existing thin-layer chromatographic methods is usually not necessary; the results remain unchanged. Compared with the conventional tank, employing 100 ml of solvent, the new tank has the following advantages: a saving of 50 to 80% on solvents; the avoidance of solvent waste ( i.e., a contribution by analysts towards environmental protection); “automatic” adjustment of the solvent development distance owing to the amount of solvent chosen; and an improvement in the separation and its reproducibility by means of layer pre-loading or by adjustment of the relative humidity in the tank.

Role of chain transfer in heterogeneous polymerization of ethylene

AbstractThe role of chain transfer was studied for the radiation‐induced polymerization of ethylene in precipitating media, namely n‐butyl alcohol, tert‐butyl alcohol and their mixtures. The affinities of those solvents for polyethylene are similar, but the chain‐transfer coefficient of n‐butyl alcohol is larger than that of tert‐butyl alcohol. The polymerizations were carried out in a reactor of 100 ml under a pressure of 300 kg/cm2, at 60°C, dose rate of 3.07 × 104–1.75 × 105 rad/hr in the presence of 50 ml of solvents. The polymerization in tert‐butyl alcohol shows the kinetic behavior characteristic of a heterogeneous polymerization, such as rate acceleration, high dose rate dependence of polymerization rate, and low dose rate dependence of polymer molecular weight, whereas the polymerization in n‐butyl alcohol does not exhibit such behavior and gives polymer having a molecular weight much lower than that of polymer obtained in tert‐butyl alcohol. The polymer formed in tert‐butyl alcohol exhibits a bimodal molecular weight distribution measured by gel permeation chromatography. In mixed tert‐butyl alcohol and n‐butyl alcohol solvent, with increasing fraction of n‐butyl alcohol, the two peaks not only shift to lower molecular weight but the higher molecular weight peak becomes relatively small. Eventually, the polymer formed in n‐butyl alcohol exhibits a unimodal distribution. Those results are well explained on the basis of the proposed scheme for heterogeneous polymerization.

Verwitterungsversuche mit organischen S�uren an einigen schwerl�slichen Fe-Pb-Zn und Cu Erzmineralen, angewendet auf die Genese des Kupferschiefers

The 1–2 mm fraction of FeS2, Fe3O4, PbS, PbSO4, ZnS, ZnCO3, Cu2S and Cu2(OH)2CO3 was dissolved in water, dilute HCl and 0.01 m organic acids (tannin, salicylic acid and citric acid) at 1 atm and 20° C. Duplicate samples of one gram each were placed in 50 ml of solvent with shaking once each day for one month at pH's of 2, 4 and 6. The pH of all the solutions was maintained by periodic addition of either HCl or NaOH. Comparing the results at pH 6, a value observed under surface conditions, the organic acids had a higher metal ion concentration because of their complexing ability. Results at pH 6 in ppm of the metal ions are shown below: For example the Fe concentration dissolved from pyrite in water was 0.02 ppm but 2.3–4.3 in the organic acids. From malachite 0.2 ppm Cu were dissolved by water but 25–1550 ppm by the organic acids. In general Cu minerals seem to be more soluble in organic acids than the Pb, Zn and Fe minerals. The different solution power of the organic acids within the experiments seems not to be caused by the crystallography of the minerals tested. Further there apparently is no preferential complexing of an organic acid with respect to a distinct anion or cation of the minerals. The experiments therefore show, that it is difficult to predict exactly which organic acid is most effective in dissolving minerals. However the experiments should apply to natural weathering conditions of ore minerals and may aid in understanding metal ion transport. For example the origin of the high Cu concentration in the sedimentary “Kupferschiefer” are more easily explained by weathering and transport of Cu in the form of organo-metallic complexes than by reaction with only water. The Cu content in organic acids is much higher than in water and the Cu concentration in the solutions now is not so strongly controlled by the solubility of Cu-cabonates and phosphates.

Ticarcillin therapy of infections.

Ticarcillin was administered as initial therapy during 73 episodes of infections occurring in 69 adults with neoplastic diseases. During the first six infections, doses of 5 gm were dissolved in 200 ml of solvent and administered intravenously over a 2-h period every 6 h. Four of six infections responded to therapy. However, two of the five Pseudomonas infections failed to respond, whereas the organisms causing the infection were sensitive to ticarcillin in vitro. During the remaining 67 infections, doses of 3.5 g were similarly dissolved and administered intravenously over a 2-h period every 4 h. The overall response to ticarcillin in these 67 infections was 43%. However, 18 of 20 Pseudomonas infections, three Proteus spp. infections, and one infection caused by H. influenzae responded. Only 1 of 7 infections caused by mixed organisms and 5 of 13 infections in which the etiologic agent could not be identified responded. Ticarcillin was ineffective against the majority of Escherichia coli and Klebsiella spp. infections, organisms which were resistant to ticarcillin in vitro. The majority of patients were neutropenic, but the response rate was not dependent on the number of circulating polymorphonuclear neutrophilic leukocytes. Superinfection occurred in seven patients. Erythematous skin rash occurred in two patients, which subsided after discontinuation of the drug. No liver or renal toxicity occurred that could be attributed to ticarcillin.