Development of a Multichannel Turbidimetric-Kinetic Photometer for the Quantitative Determination of Endotoxin

1989 ◽  
Vol 43 (5) ◽  
pp. 821-826
Author(s):  
Haruki Oishi ◽  
Yasumichi Hatayama ◽  
Masaji Fusamoto ◽  
Yoshitsugu Sakata
Keyword(s):  
Detection System ◽  
Gelation Time ◽  
Automated Measurement ◽  
Endotoxin Concentration ◽  
Coefficients Of Variation ◽  
Wide Range ◽  
Time Required ◽  
Objective Detection ◽  
Sample Dilution

A turbidimetric-kinetic photometer which monitors 64 samples simultaneously and independently has been developed for the automated measurement of endotoxin. This instrument measures the turbidity change at 660 nm in a gelation reaction of the LAL/endotoxin system and automatically scores the reaction time required to obtain a certain turbidity change as gelation time. Since a stationary dry bath incubator controls the reaction temperature of the samples at 37 ± 0.5°C and also controls the ambience of the optical system assembled into the incubator, the objective detection of gelation is provided without any disturbance from sample vibration, and the drift of the detection system is minimized. An extremely wide range for the calibration curve, such as 4 or 5 orders of magnitude of endotoxin concentration, is obtained without sample dilution. The coefficients of variation of the calculated endotoxin concentration are 4.91 to 14.0%.

An Automated Detection System for Most L-α-Amino Acids

1969 ◽  
Vol 15 (2) ◽  
pp. 154-161 ◽  
Author(s):  
K Van Dyke ◽  
C Szustkiewicz
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Detection System ◽  
Automated System ◽  
Acid Oxidase ◽  
Enzymatic Reactions ◽  
Amino Acid Oxidase ◽  
Automated Method ◽  
Wide Range

Abstract An automated system for the determination of the L-α form of the majority of amino acids is presented. The method is based upon oxidative deamination of the amino acid coupled with oxidation of o-dianisidine by hydrogen peroxide. This procedure can be used comparatively for the determination of a mixture of L-α-amino acids or for the majority of separated L-α-amino acids (especially in conjunction with column separations from urine and blood which give falsely positive identification with ninhydrin detection). The stereospecific nature of the L-α-amino acid oxidase enables the investigator to quantitate the amount of L-α-amino acid in the presence of the D-α form. From an academic viewpoint, the extreme sensitivity and wide range of the detection system make it advantageous for the study of the enzyme itself. This automated method also may be employed to follow enzymatic reactions—e.g., those catalyzed by peptidases or racemases. The methodology is extremely convenient with good reagent stability and is much more sensitive than manometric technics.

GLC Determination of Methanol in Liquids: Collaborative Study

1971 ◽  
Vol 54 (3) ◽  
pp. 558-559
Author(s):  
Donald L Andersen
Keyword(s):  
Collaborative Study ◽  
Flame Ionization Detector ◽  
Specific Method ◽  
Gas Chromatograph ◽  
Ionization Detector ◽  
Flame Ionization ◽  
Coefficients Of Variation ◽  
Sample Dilution

Abstract A rapid, specific method for methanol in aqueous and nonaqueous liquids has been developed and studied collaboratively. The method involves sample dilution with dioxane to approximately 0.4% methanol and injection into a gas chromatograph fitted with a Porapak R column and a flame ionization detector. A collaborative study, with 7 collaborators each reporting on 6 test portions, showed coefficients of variation of 2.7, 2.1, 2.3, 4.2, 1.8, and 3.5. The method has been adopted as official first action.

A Direct Carrier Distillation Procedure for the spectrographic Determination of Impurities in Uranium Tetrafluoride

1974 ◽  
Vol 28 (6) ◽  
pp. 564-568 ◽  
Author(s):  
L. S. Dale
Keyword(s):  
Simultaneous Determination ◽  
Spectral Interference ◽  
Lead Chloride ◽  
Internal Standards ◽  
Spectrographic Determination ◽  
Uranium Tetrafluoride ◽  
Coefficients Of Variation ◽  
Wide Range ◽  
Determination Of Impurities

A direct carrier distillation procedure for the determination of a wide range of impurities in uranium tetrafluoride is described. The method is based on the use of lead chloride as carrier with yttrium oxide to suppress uranium spectral interference. A deep crater electrode further aids in the reduction of spectral interference. Germanium and cobalt are used as internal standards. The method has been adopted for the simultaneous determination of Ag, l, B, Cd, Cr, Cu, Fe, Mg, Mn, Mo, Na, Ni, Si, Sn, Ti, V, and Zn with detection limits in the range 0.1 to 20 ppm and coefficients of variation ranging from 4 to 15%.

High Pressure Liquid Chromatographic Determination of Carbadox and Pyrantel Tartrate in Swine Feed and Supplements

1983 ◽  
Vol 66 (3) ◽  
pp. 602-605
Author(s):  
Dwight M Lowie ◽  
Robert T Teague ◽  
Floyd E Quick ◽  
Clarence L Foster
Keyword(s):  
High Pressure ◽  
Chromatographic Determination ◽  
High Pressure Liquid Chromatographic ◽  
Coefficients Of Variation ◽  
Wide Range ◽  
Liquid Chromatographic Determination ◽  
Reliable Procedure ◽  
Liquid Chromatographic ◽  
Pyrantel Tartrate

Abstract A rapid yet reliable procedure for the simultaneous extraction and assay of carbadox and pyrantel tartrate is described. The feed is extracted with water-acetonitrile-methanol and cleaned up on a short alumina column. The eluant is separated by high pressure liquid chromatography and the compounds are detected at different wavelengths. The drugs of interest are well resolved in all feeds studied. The procedure has also been applied to a wide range of feeds which contained either one of the drugs or both in combination. No significant interferences were observed. Spiked sample recoveries were 97% for carbadox and 101% for pyrantel tartrate. Ruggedness test coefficients of variation were 2.0% for carbadox and 2.1% for pyrantel tartrate.

Determination of Leucogentian Violet in Chicken Fat by Liquid Chromatography with Electrochemical and Ultraviolet Detection: Interlaboratory Study

1994 ◽  
Vol 77 (6) ◽  
pp. 1454-1459 ◽  
Author(s):  
Patricia G Schermerhorn ◽  
Robert K Munns
Keyword(s):  
Detection System ◽  
Uv Detection ◽  
Ultraviolet Detection ◽  
Chicken Fat ◽  
Detection Systems ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Method ◽  
Laboratory Trial ◽  
Liquid Chromatographic

Abstract A laboratory trial was completed for a liquid chromatographic method that can quantitate leucogentian violet (LGV) in chicken fat at 10 ppb. With this method, LGV is isolated from the fat matrix by a series of liquid–liquid extractions. This trial evaluated 2 detection systems: electrochemical (EC) and ultraviolet (UV). The participating laboratories determined incurred residues at 2 levels as well as fat samples fortified at 5,10, and 20 ppb. Using UV detection, the 3 laboratories reported the following range of recoveries: 71.0–89.6% at 5 ppb, 74.7–83.9% at 10 ppb, and 77.2–79.0% at 20 ppb. When these same samples were chromatographed with EC detection, the 2 reporting laboratories obtained the following average recoveries: 79.0 and 92.5% at 5 ppb, 75.9 and 85.4% at 10 ppb, and 77.3 and 79.8% at 20 ppb. The average concentrations found for the first level of incurred sample were 6.3,6.3, and 5.4 ppb with coefficients of variation (CVs) of 2.4,7.6, and 33.7%, respectively, when UV detection was used. Samples chromatographed with EC detection averaged 6.3 and 6.4 ppb with CVs of 4.0 and 8.2%, respectively. The second level of incurred sample gave average concentrations of 27.6,29.0, and 10.9 ppb with CVs of 11.0,5.0, and 42.8%, respectively, when the UV detection system was used. With the EC detector, the concentrations averaged 27.2 and 30.7 ppb with CVs of 15.7 and 3.5%, respectively.

Microwaves: Application in Electron Microscopy

1990 ◽  
Vol 48 (3) ◽  
pp. 140-141
Author(s):  
Anthony S-Y Leong ◽  
David W Gove
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Chemical Reactions ◽  
Electromagnetic Waves ◽  
Tissue Fixation ◽  
Primary Method ◽  
Dipolar Molecules ◽  
Wide Range ◽  
Time Required ◽  
Cryostat Sections

Microwaves (MW) are electromagnetic waves which are commonly generated at a frequency of 2.45 GHz. When dipolar molecules such as water, the polar side chains of proteins and other molecules with an uneven distribution of electrical charge are exposed to such non-ionizing radiation, they oscillate through 180° at a rate of 2,450 million cycles/s. This rapid kinetic movement results in accelerated chemical reactions and produces instantaneous heat. MWs have recently been applied to a wide range of procedures for light microscopy. MWs generated by domestic ovens have been used as a primary method of tissue fixation, it has been applied to the various stages of tissue processing as well as to a wide variety of staining procedures. This use of MWs has not only resulted in drastic reductions in the time required for tissue fixation, processing and staining, but have also produced better cytologic images in cryostat sections, and more importantly, have resulted in better preservation of cellular antigens.

TIME TO THE END OF PRIMARY CONSOLIDATION (EOP) OF SOFT CLAYEY SOILS: CONCERNING THE EFFECT OF ATTERBERG’S LIMIT AND CYCLIC LOADING HISTORY

2019 ◽  
Vol 128 (2B) ◽  
pp. 29-41
Author(s):  
Trần Thanh Nhàn
Keyword(s):  
Cyclic Loading ◽  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Clayey Soils ◽  
Loading History ◽  
Cyclic Shear ◽  
Wide Range ◽  
Primary Consolidation ◽  
Time Required

In order to observe the end of primary consolidation (EOP) of cohesive soils with and without subjecting to cyclic loading, reconstituted specimens of clayey soils at various Atterberg’s limits were used for oedometer test at different loading increments and undrained cyclic shear test followed by drainage with various cyclic shear directions and a wide range of shear strain amplitudes. The pore water pressure and settlement of the soils were measured with time and the time to EOP was then determined by different methods. It is shown from observed results that the time to EOP determined by 3-t method agrees well with the time required for full dissipation of the pore water pressure and being considerably larger than those determined by Log Time method. These observations were then further evaluated in connection with effects of the Atterberg’s limit and the cyclic loading history.

DINAMIKA POLITIK PERSETUJUAN BERSAMA TENTANG PENETAPAN DESA ADAT DI KABUPATEN ROKAN HULU TAHUN 2014

2017 ◽  
Vol 15 (1) ◽  
pp. 21
Author(s):  
Haryo Suganda ◽  
Raja Muhammad Amin
Keyword(s):  
Regulatory Region ◽  
Field Research ◽  
Analysis Techniques ◽  
Political Dynamics ◽  
Political Interests ◽  
Wide Range ◽  
Information Method ◽  
Qualitative Descriptive ◽  
The Village

This study is motivated the identification of policies issued by the regional Governmentof Rokan Hulu in the form of Regulatory region number 1 by 2015 on the determination of thevillage and Indigenous Village. Political dynamics based on various interests against themanufacture of, and decision-making in the process of formation of the corresponding localregulations determination of Indigenous Villages in the Rokan Hulu is impacted to a verysignificantamount of changes from the initial draft of the number i.e. 21 (twenty one) the villagebecame Customary 89 (eighty-nine) the Indigenous Villages who have passed. Type of thisresearch is a qualitative descriptive data analysis techniques. The research aims to describe theState of the real situation in a systematic and accurate fact analysis unit or related research, aswell as observations of the field based on the data (information). Method of data collectionwas done with interviews, documentation, and observations through fieldwork (field research).The results of the research on the process of discussion of the draft local regulations andmutual agreement about Designation of Indigenous Villages in the Rokan Hulu is, showed thatthe political dynamics that occur due to the presence of various political interests, rejectionorally by Villagers who were judged to have met the requirements of Draft Regulations to beformulated and the area for the set to be Indigenous Villages, and also there is a desire fromsome villages in the yet to Draft local regulations in order to set the Indigenous village , there isa wide range of interests of these aspects influenced the agreement to assign the entire localVillage which is in the Rokan Hulu become Indigenous village, and the village of Transmigrationinto administrative Villages where the initiator of the changes in the number of IndigenousVillages in the Rokan Hulu it is the desire of the local Government of its own.

scholarly journals Recent Developments in the Determination of Biomarkers of Tobacco Smoke Exposure in Biological Specimens: A Review

2021 ◽  
Vol 18 (4) ◽  
pp. 1768
Author(s):  
Hernâni Marques ◽  
Pedro Cruz-Vicente ◽  
Tiago Rosado ◽  
Mário Barroso ◽  
Luís A. Passarinha ◽  
...  
Keyword(s):  
Tobacco Smoke ◽  
Solid Phase ◽  
Smoke Exposure ◽  
Tobacco Smoke Exposure ◽  
World Health ◽  
Second Hand Smoke ◽  
Tobacco Exposure ◽  
Wide Range ◽  
Recent Developments

Environmental tobacco smoke exposure (ETS) and smoking have been described as the most prevalent factors in the development of certain diseases worldwide. According to the World Health Organization, more than 8 million people die every year due to exposure to tobacco, around 7 million due to direct ETS and the remaining due to exposure to second-hand smoke. Both active and second-hand exposure can be measured and controlled using specific biomarkers of tobacco and its derivatives, allowing the development of more efficient public health policies. Exposure to these compounds can be measured using different methods (involving for instance liquid- or gas-chromatographic procedures) in a wide range of biological specimens to estimate the type and degree of tobacco exposure. In recent years, a lot of research has been carried out using different extraction methods and different analytical equipment; this way, liquid–liquid extraction, solid-phase extraction or even miniaturized procedures have been used, followed by chromatographic analysis coupled mainly to mass spectrometric detection. Through this type of methodologies, second-hand smokers can be distinguished from active smokers, and this is also valid for e-cigarettes and vapers, among others, using their specific biomarkers. This review will focus on recent developments in the determination of tobacco smoke biomarkers, including nicotine and other tobacco alkaloids, specific nitrosamines, polycyclic aromatic hydrocarbons, etc. The methods for their detection will be discussed in detail, as well as the potential use of threshold values to distinguish between types of exposure.

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