scholarly journals Determination of Various Parameters during Thermal and Biological Pretreatment of Waste Materials

Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2262 ◽  
Author(s):  
Robert Hren ◽  
Aleksandra Petrovič ◽  
Lidija Čuček ◽  
Marjana Simonič
Keyword(s):  
Liquid Phase ◽  
Gas Phase ◽  
Rumen Fluid ◽  
Typha Latifolia ◽  
Waste Materials ◽  
Advantages And Disadvantages ◽  
Before And After ◽  
Ruminal Temperature ◽  
Lower Temperature

Pretreatment of waste materials could help in more efficient waste management. Various pretreatment methods exist, each one having its own advantages and disadvantages. Moreover, a certain pretreatment technique might be efficient and economical for one feedstock while not for another. Thus, it is important to analyze how parameters change during pretreatment. In this study, two different pretreatment techniques were applied: thermal at lower and higher temperatures (38.6 °C and 80 °C) and biological, using cattle rumen fluid at ruminal temperature (≈38.6 °C). Two different feedstock materials were chosen: sewage sludge and riverbank grass (Typha latifolia), and their combinations (in a ratio of 1:1) were also analyzed. Various parameters were analyzed in the liquid phase before and after pretreatment, and in the gas phase after pretreatment. In the liquid phase, some of the parameters that are relevant to water quality were measured, while in the gas phase composition of biogas was measured. The results showed that most of the parameters significantly changed during pretreatments and that lower temperature thermal and/or biological treatment of grass and sludge is suggested for further applications.

Determination of Amphetamine and Methylamphetamine by Gas-liquid Chromatography (Head Space)

1983 ◽  
Vol 2 (2) ◽  
pp. 391-393 ◽  
Author(s):  
D. Martinez ◽  
M.P. Gimenez
Keyword(s):  
Liquid Chromatography ◽  
Solvent Extraction ◽  
Liquid Phase ◽  
Gas Phase ◽  
Urine Sample ◽  
Urine Samples ◽  
Gas Liquid Chromatography ◽  
Flame Detection ◽  
Therapeutic Doses

1 A method for determining amphetamine and methylamphetamine in urine by gas-liquid chromatography is described. 2 Chromatography is performed on a 10% Apiezon L, 10% KOH column with alkali-flame detection (NPD). This method avoids the losses of these volatile substances which are known to occur when solvent extraction is used. An alkalinized urine sample (1 ml) is introduced into a sealed vial which is heated in a water bath at 70°C for 20 min. A 1 ml portion of the gas phase in equilibrium with the liquid phase is chromatographed. 3 Amphetamine and methylamphetamine can be detected and measured in urine samples after single therapeutic doses of the drugs.

scholarly journals Sensitivity Increase in Headspace Analysis of Hydrocarbons in Water by Using Online Selective Elimination of Gas Extractant

Separations ◽  
2022 ◽  
Vol 9 (1) ◽  
pp. 15
Author(s):  
Oleg V. Rodinkov ◽  
Alexey Y. Pisarev ◽  
Leonid N. Moskvin ◽  
Aleksandra S. Bugaichenko ◽  
Pavel N. Nesterenko
Keyword(s):  
Gas Phase ◽  
Chromatographic Analysis ◽  
Headspace Analysis ◽  
Selective Absorption ◽  
Novel Approach ◽  
Headspace Gas ◽  
Selective Elimination ◽  
Before And After ◽  
Aliphatic And Aromatic Hydrocarbons

In this study, a novel approach in headspace gas chromatographic analysis using the selective absorption of the gas extractant during concentration of the analytes was developed. The carbon dioxide used as the gas extractant was removed from the sample flow by passing it through a column packed with microdispersed sodium hydroxide granules. The analytical capabilities of the suggested method were illustrated by the determination of aliphatic and aromatic hydrocarbons in water. We established that this method allows the preconcentration of analytes in the gas phase to be increased proportionally to the volume ratios of the gas extractant before and after absorption, while the analyte limits of detection decrease 30-fold. For example, benzene can be detected in water at a concentration of 0.5 μg/L.

Determination of Azole Fungicides in Atmospheric Samples Collected in the Canadian Prairies by LC/MS/MS

2012 ◽  
Vol 95 (5) ◽  
pp. 1350-1356 ◽  
Author(s):  
Renata Raina ◽  
Erika Smith
Keyword(s):  
Gas Phase ◽  
Detection Limits ◽  
Early Summer ◽  
Canadian Prairies ◽  
Agricultural Region ◽  
Air Sample ◽  
Lower Temperature ◽  
Atmospheric Concentrations ◽  
Azole Fungicides

Abstract An LC/MS/MS method has been developed for the determination of azole fungicides in the atmosphere at low pg/m3 concentrations. Detection limits in the range of 0.16 to 1.2 pg/m3 for a weekly air sample were obtained for the 31 fungicides analyzed. This work represents the first detection of propiconazole, prothioconazole-desthio, and trace levels of hexaconazole in gas phase atmospheric samples collected in a Canadian agricultural region. Samples were collected during April–October 2010 at Bratt's Lake, Saskatchewan, in the Canadian prairies where there was known historical use of selected azole fungicides. Atmospheric concentrations were above detection limits only during June–August 2010, with maximum concentrations occurring in July at 77.9 and 37.5 pg/m3 for propiconazole and prothioconazole-desthio, respectively. Gas phase atmospheric concentrations of propiconazole and prothioconazole-desthio increased following a spring and early summer with higher than normal daily precipitation. These azole fungicides showed the largest gas phase concentrations during periods of lower temperature and during sampling events with at least 1 day with no precipitation. The higher atmospheric gas phase concentrations of each azole fungicide were observed on different days, indicating different formulations may be in use in the prairie agricultural region.

scholarly journals Determination of Histidine and Related Compounds in Rumen Fluid by Liquid Chromatography

2000 ◽  
Vol 83 (1) ◽  
pp. 8-15 ◽  
Author(s):  
Shaila Wadud ◽  
Ryoji Onodera ◽  
Mamun M Or-Rashid ◽  
Mohammad R Amin
Keyword(s):  
Phosphate Buffer ◽  
Rumen Fluid ◽  
Direct Injection ◽  
Potassium Phosphate ◽  
Potassium Phosphate Buffer ◽  
Absorbance Detection ◽  
Before And After ◽  
Chromatographic Procedure ◽  
Liquid Chromatographic

Abstract A liquid chromatographic procedure was developed for quantitative determination of histidine (His), histidinol (HDL), histamine (HTM), urocanic acid (URA), imidazolepyruvic acid (ImPA), imidazoleacetic acid (ImAA), and imidazolelactic acid (ImLA) in rumen fluid. The method is based on direct injection analysis by UV absorbance detection at 220 nm. The separation was performed under 2 different chromatographic conditions on a LiChrospher 100 NH2 column. In the first chromatographic system, the mobile phase used for isocratic elution was 67 mM potassium phosphate buffer (monobasic and dibasic) pH 6.45–90% acetonitrile in water (21 + 79); in the second system, an acetonitrile gradient in 63 mM potassium phosphate buffer (monobasic) pH 3.0, obtained by addition of 60 mM phosphoric acid, was used. Analyses of both systems were completed within 32 and 25 min, respectively. The limits of detection of these compounds were (μM): His, 2.8; HDL, 3.7; HTM, 4.0; URA, 0.75; ImPA, 4.7; ImAA, 1.2; and ImLA, 1.3. Recovery of these compounds added to rumen fluid was 97.4–103.0% within a 1-day study and 95.4–99.0% on different day studies. Detectable levels of His were found in the deproteinized rumen fluid of goats, with average concentrations of 16.10, 10.43, 11.14, and 13.62 μM in the rumen fluid collected before the morning feeding and 2, 4, and 6 h after feeding, respectively. HDL, HTM, URA, ImPA, ImAA, and ImLA were not detected in the rumen fluid before and after feeding. Trp, Phe, and Tyr were also identified in the rumen fluid, with average concentrations of 8.25, 29.04, and 12.6 μM, respectively, before the morning feeding.

Determination of the dispersion of supported Pt particles by gas-phase and liquid-phase measurements

2009 ◽  
Vol 10 (6) ◽  
pp. 1002-1005 ◽  
Author(s):  
Hilal Kivrak ◽  
Ágnes Mastalir ◽  
Zoltán Király ◽  
Deniz Uner
Keyword(s):  
Liquid Phase ◽  
Gas Phase ◽  
Phase Measurements

Comparison study on portable wind tunnel system and isolation chamber for determination of VOCs from areal sources

1996 ◽  
Vol 34 (3-4) ◽  
pp. 583-589 ◽  
Author(s):  
Kaiyun Jiang ◽  
Ralph Kaye
Keyword(s):  
Liquid Phase ◽  
Wind Tunnel ◽  
Gas Phase ◽  
Emission Rates ◽  
Isolation Chamber ◽  
Chamber Method ◽  
South Wales ◽  
The University ◽  
Liquid Surfaces

Many environmental monitoring programmes require the determination of volatile organic compounds (VOCs) emitted from large areal sources including liquid surfaces. A study was carried out to compare existing sampling techniques. Both the isolation chamber method (static technique) and the wind tunnel method (dynamic technique) were examined. A review of the mechanisms suggested that static techniques would not be appropriate for determining emissions from liquid surfaces which result from gas phase controlled volatilisation processes. A portable wind tunnel developed at the University of New South Wales and an isolation chamber built to USEPA specification were used in an experimental study of emissions from aqueous liquid surfaces. An acetone solution was chosen to represent gas phase controlled volatilisation processes. Toluene and methyl ethyl ketone in aqueous solution were chosen, respectively to investigate (1) liquid phase controlled volatilisation processes, and (2) combined gas and liquid phase controlled volatilisation processes. It was found that the use of the isolation chamber method resulted in different degrees of underestimation of the emission rates for the above three compounds. The wind tunnel method is suitable for sampling all VOC emissions from areal sources.

The Plasmin Inhibitors of Plasma

1964 ◽  
Vol 12 (01) ◽  
pp. 119-125 ◽  
Author(s):  
Y Shamash ◽  
A Rimon
Keyword(s):  
Human Plasma ◽  
New Method ◽  
Normal Amount ◽  
Caseinolytic Activity ◽  
Before And After ◽  
Plasmin Inhibitors

SummaryA new method for the assay of plasmin inhibitors in human plasma is described. The method consists of determination of the caseinolytic activity of a standard plasmin solution before and after incubation with the inhibitor, with lysine added to the mixture as a stabilizer of plasmin. Using this method, it was found that plasma contains enough inhibitors to inactivate 30 caseinolytic units of plasmin, or 10 times the normal amount of plasminogen in human plasma.

FRACTIONAL DETERMINATIONS OF URINARY 17-KETOSTEROIDS IN HYPEREMESIS GRAVIDARUM

1962 ◽  
Vol 41 (1) ◽  
pp. 123-128 ◽  
Author(s):  
Pentti A. Järvinen ◽  
Sykkö Pesonen ◽  
Pirkko Väänänen
Keyword(s):  
Hyperemesis Gravidarum ◽  
First Trimester ◽  
Control Group ◽  
Before And After ◽  
Daily Urine ◽  
First Trimester Of Pregnancy ◽  
The Difference

ABSTRACT The fractional determination of 17-ketosteroids in the daily urine was performed in nine cases of hyperemesis gravidarum and in four control cases, in the first trimester of pregnancy both before and after corticotrophin administration. The excretion of total 17-KS is similar in the two groups. Only in the hyperemesis group does the excretion of total 17-KS increase significantly after corticotrophin administration. The fractional determination reveals no difference between the two groups of patients with regard to the values of the fractions U (unidentified 17-KS), A (androsterone) and Rest (11-oxygenated 17-KS). The excretion of dehydroepiandrosterone is significantly higher in the hyperemesis group than in the control group. The excretion of androstanolone seems to be lower in the hyperemesis group than in the control group, but the difference is not statistically significant. The differences in the correlation between dehydroepiandrosterone and androstanolone in the two groups is significant. The high excretion of dehydroepiandrosterone and low excretion of androstanolone in cases of hyperemesis gravidarum is a sign of adrenal dysfunction.

DETERMINATION OF BLOOD CORTICOIDS USING THE IN VITRO RESIN UPTAKE OF 3H-PREDNISOLONE

1968 ◽  
Vol 57 (1) ◽  
pp. 23-32 ◽  
Author(s):  
Hironori Nakajima ◽  
Mitsunori Murala ◽  
Masumitsu Nakata ◽  
Takeshi Naruse ◽  
Seiji Kubo
Keyword(s):  
Thyroid Function Test ◽  
Normal Subjects ◽  
Adrenal Function ◽  
Function Test ◽  
Before And After ◽  
Adrenal Response ◽  
Suppression Test

ABSTRACT The in vitro resin uptake of 3H-prednisolone was used for the determination of blood cortisol after addition of radioactive prednisolone followed by Amberlite CG 400 Type 1 to the test serum, and incubation of the mixture. The radioactivity of the supernatant was compared before and after the addition of the resin. The principle of this method is similar to that of the 131I-triiodothyronine resin uptake for the thyroid function test. The tests for the specificity, reproducibility and sensitivity gave satisfactory results. The mean basal value ± SD of the 3H-prednisolone resin uptake was 35.3 ± 9.2% in normal subjects, and 27.1 ± 4.8% in pregnant women. This method was valid in various adrenal function tests, i. e. the adrenal circadian rhythm, corticotrophin (ACTH) test, dexamethasone suppression test and the adrenal response to lysine-8-vasopressin. It proved to be a sensitive indicator of the adrenal function. These results suggest that this method should be useful for a routine adrenal function test.

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