Evaluierung von Endotoxinproben – Vergleich von Analysen sowie Transport- und Lagerungsbedingungen durch standardisierte Proben/Production of standardized endotoxin dust samples for comparison of transport, storage and analysis of workplace relevant samples

Gefahrstoffe ◽  
2020 ◽  
Vol 80 (09) ◽  
pp. 335-341
Author(s):  
C. Pogner ◽  
M. Gorfer ◽  
A. Kolk
Keyword(s):  
Quality Control ◽  
Chronic Diseases ◽  
Room Temperature ◽  
Test Chamber ◽  
Established Method ◽  
Air Samples ◽  
Endotoxin Activity ◽  
Interlaboratory Trial ◽  
High Concentrations ◽  
Dust Filter

Die Inhalation von Endotoxinen in hohen Konzentrationen kann zu akuten und chronischen Erkrankungen führen. Deshalb ist vor allem an Arbeitsplätzen die Erhebung und – wenn möglich – die Reduktion der Konzentration wichtig. Für die Sammlung, Verarbeitung (Transport, Lagerung, Extraktion) und Analyse von Endotoxinen aus Luftproben an Arbeitsplätzen gibt es zurzeit jedoch keine umfassenden oder aktuell veröffentlichten Verfahren zu qualitätssichernden Kriterien und Maßnahmen. Das führt zu unterschiedlichen Methoden und nicht vergleichbaren Ergebnissen. In der Qualitätssicherung sind Ringversuche ein wichtiger Bestandteil für die Überwachung der Einhaltung von Standardverfahren bei der Analyse. Um die quantitativen Nachweise von Endotoxinen zu vergleichen und Einflüsse durch Lagerung und Transport zu untersuchen, sind Proben notwendig, die kontrolliert und wiederholbar mit definierten Mengen an endotoxinhaltiger Luft beaufschlagt werden. Das in dieser Publikation beschriebene, entwickelte Prozedere erlaubt die gleichzeitige Sammlung von acht Proben unter kontrollierten Bedingungen in einer Bioaerosoltestkammer. Durch Wiederholungen kann damit eine Vielzahl von einheitlich beaufschlagten Filterproben hergestellt werden. Mithilfe solcher Proben konnten Einflüsse von Lagerungszeit und -bedingungen untersucht werden. In einem anschließenden Testringversuch bestimmten neun Labore die Endotoxinaktivitäten von Proben mit verschiedenen Staubkon- zentrationen. Die Labore verwendeten zur Analyse jeweils das in ihrem Haus etablierte Standardverfahren. Während eine Lagerung bei Raumtemperatur von bis zu 14 Tagen keinen Einfluss auf das Ergebnis hat, konnte eine deutliche Reduktion der gemessenen Endotoxingehalte nach einer Lagerung der Extrakte bei -80 °C ermittelt werden.   SUMMARY The inhalation of high concentrations of endotoxins can lead to acute and chronic diseases. Until now there are no extensive and up-to-date criteria and measures for quality control of sampling, processing (transport, storage, extraction) and analysis of endotoxin containing air samples. For quality control purposes, standardized samples have to be produced in a controlled and reproducible way with defined concentrations or endotoxin containing bioaerosols. In this project we developed a setup to produce eight samples simultaneously in a reproducible way to obtain a high number of uniform filter samples, by the use of a bioaerosol test chamber. Using these samples, we investigated storage and transport conditions. After that in a testrun of an interlaboratory trial endotoxin activity of the test samples was determined by nine laboratories. All participants of this trial used the well established method of their lab for extraction and analysis. Our results show, that storage of dust filter samples up to two weeks on room temperature had no significant reduction, but storage of extracts at -80°C showed clear reduction of measured endotoxin activity.

scholarly journals Using Reproducible Data Visualizations to Augment Decision-Making During Suppression of Small Counts

2020 ◽  
Vol 5 (5) ◽  
Author(s):  
Andriy Koval ◽  
Kate Smolina ◽  
Anthony Leamon
Keyword(s):  
Decision Making ◽  
British Columbia ◽  
Quality Control ◽  
Chronic Diseases ◽  
Human Error ◽  
Data Systems ◽  
Quality Control Tool ◽  
Human Decision ◽  
And Function ◽  
Function Dependency

IntroductionWhen reporting disease rates to the public, a health system must take precaution to protect released data from re-identification risks. While specific guidelines and methods vary across data systems and governances 1 , redaction of cells with small values is a key component in any approach for preparing data for public release. These preparations, when conducted manually, have proven to be arduous, time consuming, and prone to human error. Although finding a “small” value (e.g. “< 5 ” ) is straightforward, detecting conditions in which suppressed values could be recalculated from related cells involves human judgement. Objectives and ApproachGuided by the real-world objective to reports the rates of chronic diseases in British Columbia, we aimed to design a reproducible workflow that would augment human decision-making and offer a nimble quality control tool, approachable by epidemiologists without technical background. Our workflow (1) splits data into disease-by-year data frames of a specific form, (2) applies a sequence of algorithms trained to recognize conditions that made recalculation of suppressed values possible and (3) prints a graph for each case of suggested automatic redaction to be confirmed by a human. ResultsThe augmented suppression system was successfully integrated into the maintenance of Chronic Disease Dashboard, an online reporting tool of the Observatory for Population and Public Health designed to address the gap in surveillance of chronic diseases in British Columbia. Anticipating the evolution of suppression logic, we isolated the logical tests responsible for redaction and provided several options to vary the degree of preserved information. Conclusion / ImplicationsInstead of employing a complex generalizable solution, we make a case for organizing the procedure for small cell redaction as a data visualization task, allowing for straightforward quality control of suppression decision and thus more approachable to a non-technical audience, as well as for employing such learning devices as workflow maps and function dependency trees for structuring applied projects and ensuring their reproducibility.

scholarly journals MUTATION OF THE BACILLUS OF RABBIT SEPTICEMIA

1922 ◽  
Vol 35 (4) ◽  
pp. 561-574 ◽  
Author(s):  
Paul H. De Kruif
Keyword(s):  
Room Temperature ◽  
Relative Number ◽  
Pure Line ◽  
Rabbit Serum ◽  
Type D ◽  
Pure Cultures ◽  
High Concentrations ◽  
Distinct Maximum ◽  
Made In

Type G microbes, discovered in pure cultures of the rabbit septicemia bacillus, have been demonstrated to arise from the parent D form by mutation. The D → G mutation takes place in broth cultures of pure-line strains of Microbe D, when these are kept for several days without transplant at 37°C., or at room temperature, or in the ice box. The mutation is greatly inhibited by filtrates from 6 and 24 hour cultures of Microbe D, and to some extent by filtrates from 48 hour cultures. The process of transformation takes place to a very slight extent or not at all in undiluted rabbit serum, but Type G colonies subcultured to this medium do not revert to the parent D form. The D → G change is strongly inhibited in cultures made in simple beef infusion, or in 5 per cent rabbit serum-beef infusion. Peptone would seem to be the constituent of plain broth which favors the process. In high concentrations of peptone, the mutation is rapid and may reach a degree of 90 per cent of the total organisms in 5 to 6 days. A distinct maximum of the relative number of Type G colonies as compared to the parent Type D is observable in plain broth and in some concentrations of peptone, when these are kept at 37°C. for some days without transplant. Subsequent tests show the concentration of Type G microbes to diminish. The change in acid agglutination optimum exhibited by the mutant G forms implies a distinct change in bacterial protoplasm and would seem to be one of the most fundamental mutations so far described.

Decontamination of Bacillus Spores with Formaldehyde Vapor Under Varied Environmental Conditions

2020 ◽  
pp. 153567602092697
Author(s):  
Young W. Choi ◽  
Michelle M. Sunderman ◽  
Martha W. McCauley ◽  
William R. Richter ◽  
Zachary J. Willenberg ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Time Course ◽  
Test Chamber ◽  
Air Concentration ◽  
Air Samples ◽  
Circulating Water ◽  
Surface Areas ◽  
Formaldehyde Vapor ◽  
Chamber Temperature ◽  
Bacillus Spores

Introduction: This effort investigated formaldehyde vapor characteristics under various environmental conditions by the analyses of air samples collected over a time-course. This knowledge will help responders achieve desired formaldehyde exposure parameters for decontamination of affected spaces after a biological contamination incident. Methods: Prescribed masses of paraformaldehyde and formalin were sublimated or evaporated, respectively, to generate formaldehyde vapor. Adsorbent cartridges were used to collect air samples from the test chamber at predetermined times. A validated method was used to extract the cartridges and analyze for formaldehyde via liquid chromatography. In addition, material demand for the formaldehyde was evaluated by inclusion of arrays of Plexiglas panels in the test chamber to determine the effect of varied surface areas within the test chamber. Temperature was controlled with a circulating water bath connected to a radiator and fan inside the chamber. Relative humidity was controlled with humidity fixed-point salt solutions and water vapor generated from evaporated water. Results: Low temperature trials (approximately 10°C) resulted in decreased formaldehyde air concentrations throughout the 48-hour time-course when compared with formaldehyde concentrations in the ambient temperature trials (approximately 22°C). The addition of clear Plexiglas panels to increase the surface area of the test chamber interior resulted in appreciable decreases of formaldehyde air concentration when compared to an empty test chamber. Conclusion: This work has shown that environmental variables and surface-to-volume ratios in the decontaminated space may affect the availability of formaldehyde in the air and, therefore, may affect decontamination effectiveness.

An RP-HPLC-UV Method with SPE for Cefotaxime in All-in-One Total Parenteral Nutritional Admixtures: Application to Stability Studies

2013 ◽  
Vol 96 (2) ◽  
pp. 290-294 ◽  
Author(s):  
Muhammad Shahid Iqbal ◽  
Mohd Baidi Bahari ◽  
Yusrida Darwis ◽  
Muhammad Zahid Iqbal ◽  
Amer Hayat ◽  
...  
Keyword(s):  
Particle Size ◽  
Mobile Phase ◽  
Room Temperature ◽  
Ammonium Acetate ◽  
Stability Studies ◽  
Rp Hplc ◽  
Accuracy And Precision ◽  
Degradation Rates ◽  
High Concentrations ◽  
Spe Method

Abstract A simple and selective RP-HPLC-UV method with SPE was developed and validated for the quantification of cefotaxime in all-in-one total parenteral nutrition (AIO-TPN) admixtures. Chromatographic separation was achieved on a 5 μm particle size C18 DB column (250 × 4.6 mm id) using the mobile phase ammonium acetate (25 mM, pH 4.0)–50% acetonitrile in methanol (80 + 20, v/v). The flow rate was 0.9 mL/min and the detection wavelength was 254 nm. The analyte was extracted from AIO-TPN admixtures by means of an SPE method. The cefotaxime calibration curve was linear over a concentration range of 100–1400 μg/mL with a correlation coefficient of ≥0.9994. The intraday accuracy and precision for cefotaxime were ≤–3.15 and ≤3.08%, respectively, whereas the interday accuracy and precision were ≤–2.48 and ≤2.25%, respectively. The method was successfully applied to stability studies of cefotaxime in the presence of micronutrients together with low and high concentrations of macronutrients in AIO-TPN admixtures. Cefotaxime was degraded by 13.00 and 26.05% at room temperature (25 ± 2°C) after 72 h in low and high macronutrient concentration formulations of AIO-TPN admixtures, respectively. The values of cefotaxime degradation rates for low and high macronutrient concentration formulations of AIO-TPN admixtures were –0.164 and –0.353, respectively. These results indicated that there was higher rate of degradation in the AIO-TPN admixture formulations containing high concentrations of macronutrients.

Simple Manual Procedure for Determination of Serum Triglycerides

1975 ◽  
Vol 21 (6) ◽  
pp. 768-770 ◽  
Author(s):  
Jose Mendez ◽  
Barry Franklin ◽  
Harry Gahagan
Keyword(s):  
Quality Control ◽  
Calibration Curve ◽  
Room Temperature ◽  
Extraction Procedure ◽  
Serum Triglycerides ◽  
Modified Method ◽  
Color Development ◽  
Significant Difference ◽  
Control Samples

Abstract We describe a modified method for determining serum triglycerides (triacylglycerols), which is based on the heptane extraction procedure of Gottfried and Rosenberg [Clin. Chem. 19, 1077 (1973)] with the stable saponification, oxidation, and color development reagents of Neri and Frings [Clin. Chem. 19, 1201 (1973)]. This modified method eliminates one heating step, reduces saponification time to 5 min, absorbances are read at room temperature, and the calibration curve is linear to 3.0 g/liter. A sample comparison between the proposed method and the automated Block and Jarrett [Am. J. Med. Technol. 35, 1 (1969)] procedure showed no significant difference (r = 0.98). The coefficient of variation (47 duplicate samples) for the modified method was 6.3%. Further validation was obtained from analysis of quality-control samples; the proposed method gave equivalent values.

Liquid Control Materials for Haemoglobins A2 and F: A One-Year Interlaboratory Evaluation

1985 ◽  
Vol 22 (3) ◽  
pp. 257-260 ◽  
Author(s):  
Carlo Franzini
Keyword(s):  
Quality Control ◽  
Liquid State ◽  
Internal Quality Control ◽  
Internal Quality ◽  
Interlaboratory Trial ◽  
Control Schemes ◽  
One Year

Stabilised haemolysates, to be stored at −20°C in the liquid state, have been evaluated in an interlaboratory trial: haemoglobin A2 and haemoglobin F levels were stable for at least 1 year. Since the materials can be very easily prepared in each laboratory, they appear to meet the requirements for use in internal quality-control schemes, for the assay of both haemoglobin fractions.

Addition of triglyceride to serum for use in quality control and reference.

1976 ◽  
Vol 22 (8) ◽  
pp. 1299-1301 ◽  
Author(s):  
D P Bonderman ◽  
G J Proksch ◽  
P W Bonderman
Keyword(s):  
Quality Control ◽  
Human Serum ◽  
Room Temperature ◽  
Water Soluble ◽  
Bovine Serum Albumin Solution ◽  
Albumin Solution ◽  
Protein Preparation ◽  
Simple Method ◽  
Analytical Recovery ◽  
Triton X

Abstract We describe a simple method in which a water-soluble mixture of triocatanoin and a surfactant, "Triton X-114," are used in preparing solutions of triglycerides (triacylglycerols) in either human serum, solutions of albumin, or water. Analytical recovery added triglyceride was quantitative by two methods. The addition did not affect results of analyses for 18 other commonly measured constitutents of serum. When the triglyceride was added to either lipid-depleted human serum or bovine serum albumin solution and lyophilized, subsequent solutions were clear. The triglyceride/protein preparation was stable in lyophilized form for a year and in reconstituted serum for five days at 5 degrees C. Aquenous solutions appear to be stable indefinitely at room temperature.

Effect of storage temperature and shaking rate on pH and blood-gas results for two quality-control products.

1988 ◽  
Vol 34 (9) ◽  
pp. 1910-1912 ◽  
Author(s):  
K W Ryder ◽  
S J Jay ◽  
M R Glick ◽  
J R Woods
Keyword(s):  
Quality Control ◽  
Room Temperature ◽  
Storage Temperature ◽  
Control Program ◽  
Blood Gas ◽  
Quality Control Program ◽  
Storage Temperatures

Abstract Directions for pre-analytical handling of ampules of two commercially available aqueous quality-control products (contrlL and G.A.S.) contain vague instructions such as "store at room temperature" and "shake vigorously" before analysis. We examined the effect of different storage temperatures (25, 31, and 38 degrees C) and shaking rate (one, two, and four shakes per second) on pH and blood-gas results. For both products, increasing the storage temperature significantly decreased pO2 results, the magnitude of the bias being greatest for those solutions with the highest O2 tensions. However, increasing the shaking rate partly offset this bias. Increasing storage temperature also decreased results for pCO2 and increased results for pH for both manufacturers' ampules with the highest CO2 tensions, and this bias was not offset by increasing the shaking rate. We conclude that both storage temperature and shaking rate must be precisely defined and carefully monitored before these products are used in a quality-control program.

The Effect of Concentration, Thermal Processing, and Storage Temperature on the Interaction Between Alpha-Ketoglutaric Acid and Tryptophan

1975 ◽  
Vol 38 (10) ◽  
pp. 573-580 ◽  
Author(s):  
N. T. CHU ◽  
F. M. CLYDESDALE
Keyword(s):  
Acid Concentration ◽  
Thermal Processing ◽  
Room Temperature ◽  
Storage Temperature ◽  
Individual Effects ◽  
High Concentrations ◽  
Processing And Storage ◽  
And Storage

Formation of colored compounds caused by the interaction of α-ketoglutaric acid and tryptophan was followed spectrophotmetrically at 470 and 620 nm. It was found that the rate of formation of these colored compounds was effected by the concentration of α-ketoglutaric acid and/or tryptophan. High concentrations of both α-ketoglutaric acid and tryptophan caused the greatest concentration of such colored compounds, but singly, α-ketoglutaric acid concentration was more effective than that of tryptophan. The amount of colored compounds formed after storage at 75 F was not altered by processing, since both processed and unprocessed samples showed the same concentration after storage. The interaction mixtures stored at 38 F proceeded at very slow rates compared with those stored at 75 F. The results also indicated that individual effects caused by processing were overcome by storage at room temperature (75 F) since all samples were similar after storage.

WO3-Based Sensor Based on Hall Effect for NO2 Detection: Designed and Investigation

2010 ◽  
Vol 148-149 ◽  
pp. 1042-1046
Author(s):  
Jin Yang Lin ◽  
Yong Ai Zhang ◽  
Ling Jie Wang ◽  
Tai Liang Guo
Keyword(s):  
Magnetic Field ◽  
Response Time ◽  
Hall Effect ◽  
Tungsten Trioxide ◽  
Recovery Time ◽  
Room Temperature ◽  
Gas Sensing ◽  
Test Chamber ◽  
Tungsten Filament ◽  
Gas Sensing Properties

Novel tungsten oxide sensors were fabricated based on Hall Effect and their NO2 gas sensing properties were examined. Tungsten trioxide was grown by vapor evaporation of metal tungsten filament in an oxygen atmosphere. A WO3 thick film was deposited on the four Au electrode to be a WO3 sensor. The sensor was tested between magnetic field in a plastic test chamber. The gas sensing experiment revealed that at the NO2 concentration of 40 ppm, a sensitivity of 3.27, a response time of 36 s, and a recovery time of 45 s were observed at room-temperature. The effect of WO3 based on Hall Effect on the sensing characteristic is discussed.

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