Ammonium compounds in stratospheric aerosols

Tellus B ◽  
1986 ◽  
Vol 38B (1) ◽  
pp. 62-66 ◽  
Author(s):  
E. K. BIGG
Keyword(s):  
Ammonium Compounds ◽  
Stratospheric Aerosols

scholarly journals Ammonium compounds in stratospheric aerosols

Tellus B ◽  
1986 ◽  
Vol 38 (1) ◽  
pp. 62-66 ◽  
Author(s):  
E. K. Bigg
Keyword(s):  
Ammonium Compounds ◽  
Stratospheric Aerosols

Determination of quaternary ammonium compounds in food products by the method of ultra-performance liquid chromatography/high resolution mass-spectrometry

2020 ◽  
Vol 86 (8) ◽  
pp. 23-31
Author(s):  
V. G. Amelin ◽  
D. S. Bolshakov
Keyword(s):  
Mass Spectrometry ◽  
High Resolution ◽  
Quaternary Ammonium ◽  
High Resolution Mass Spectrometry ◽  
Food Products ◽  
Quaternary Ammonium Compounds ◽  
High Resolution Mass ◽  
Ammonium Compounds ◽  
Resolution Mass

The goal of the study is developing a methodology for determination of the residual amounts of quaternary ammonium compounds (QAC) in food products by UHPLC/high-resolution mass spectrometry after water-acetonitrile extraction of the determined components from the analyzed samples. The identification and determination of QAC was carried out on an «UltiMate 3000» ultra-high-performance liquid chromatograph (Thermo Scientific, USA) equipped with a «maXis 4G» high-resolution quadrupole-time-of-flight mass spectrometric detector and an ion spray «ionBooster» source (Bruker Daltonics, Germany). Samples of milk, cheese (upper cortical layer), dumplings, pork, chicken skin and ground beef were used as working samples. Optimal conditions are specified for chromatographic separation of the mixture of five QAC, two of them being a mixture of homologues with a linear structure (including isomeric forms). The identification of QAC is carried out by the retention time, exact mass of the ions, and coincidence of the mSigma isotopic distribution. The limits for QAC detection are 0.1 – 0.5 ng/ml, the determination limits are 1 ng/ml for aqueous standard solutions. The determinable content of QAC in food products ranges within 1 – 100 ng/g. The results of analysis revealed the residual amount of QAC present in all samples, which confirms data of numerous sources of information about active use of QAC-based disinfectants in the meat and dairy industry. The correctness of the obtained results is verified by introduction of the additives in food products at a level of 10 ng/g for each QAC. The relative standard deviation of the analysis results does not exceed 0.18. The duration of the analysis is 30 – 40 min.

Modern devices for treatment of the surgeon’s hands and the surgical field (literature review)

2020 ◽  
pp. 41-50
Author(s):  
Artem Mikhailovich Morozov ◽  
◽  
Alexey Nikolaevich Sergeev ◽  
Gennady Alexandrovich Dubatolov ◽  
Nikolay Alexandrovich Sergeev ◽  
...  
Keyword(s):  
Cost Effective ◽  
Surgical Infection ◽  
Operating Field ◽  
Functional Additives ◽  
Literary Sources ◽  
Film Forming ◽  
Key Points ◽  
Surgical Field ◽  
Ammonium Compounds ◽  
Active Substances

The aim – analyze modern Russian and foreign literary sources in order to determine modern means for treating the hands of the surgeon and the operating field. Results. One of the key points in the prevention of surgical infection is the treatment of the surgeon’s hands and the operating field with effective skin antiseptics in order to destroy pathogenic and opportunistic microorganisms that colonize intact skin. In modern practice, skin antiseptics are predominantly used containing alcohols as active substances, in particular ethyl, propyl and isopropyl, halogenated substances such as iodine and iodophores, guanidines, which include chlorhexidine digluconate, as well as quaternary ammonium compounds. Moreover, the most widespread are combined preparations containing several active substances and functional additives, which makes it possible to neutralize the negative properties of various active substances. Also, an interesting and promising direction is the use of polymer operating films or film-forming antiseptics. Currently, research is being actively carried out aimed at finding and developing modern highly effective antiseptic agents and their rational combinations that meet the necessary requirements, are optimal in their properties, cost-effective and comfortable to use.

Determination of Organic Bases by Ion-Pair Extraction Polarography Using Orange II as Counter Ion

1992 ◽  
Vol 57 (11) ◽  
pp. 2272-2278 ◽  
Author(s):  
Václav Koula ◽  
Daria Kučová ◽  
Jiří Gasparič
Keyword(s):  
Model Compound ◽  
Differential Pulse ◽  
Ion Pair ◽  
Differential Pulse Polarography ◽  
Orange Ii ◽  
Organic Bases ◽  
Counter Ion ◽  
Pulse Polarography ◽  
Ammonium Compounds

The combination of ion-pair extraction and differential pulse polarography is shown to be a method suitable for the determination of 10-7 mol l-1 concentrations of organic bases of quaternary ammonium compounds. Orange II (4-[2-hydroxy-1-naphtyl]azobenzenesulfonic acid) was found to be an appropriate polarographically active counter-ion. The proposed method was used for the determination of tetrapentylammonium bromide (as model compound), Septonex ([1-(ethoxycarbonyl)-pentadecyl]trimethylammonium bromide) and codeine.

scholarly journals Phenotypic and Genotypic Properties of Fluoroquinolone-Resistant, qnr-Carrying Escherichia coli Isolated from the German Food Chain in 2017

2021 ◽  
Vol 9 (6) ◽  
pp. 1308
Author(s):  
Katharina Juraschek ◽  
Carlus Deneke ◽  
Silvia Schmoger ◽  
Mirjam Grobbel ◽  
Burkhard Malorny ◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
Point Mutations ◽  
Beta Lactamase ◽  
Resistance Development ◽  
Extended Spectrum Beta Lactamase ◽  
E Coli ◽  
German Food ◽  
Sequence Types ◽  
Ammonium Compounds ◽  
Additional Point

Fluoroquinolones are the highest priority, critically important antimicrobial agents. Resistance development can occur via different mechanisms, with plasmid-mediated quinolone resistance (PMQR) being prevalent in the livestock and food area. Especially, qnr genes, commonly located on mobile genetic elements, are major drivers for the spread of resistance determinants against fluoroquinolones. We investigated the prevalence and characteristics of qnr-positive Escherichia (E.) coli obtained from different monitoring programs in Germany in 2017. Furthermore, we aimed to evaluate commonalities of qnr-carrying plasmids in E. coli. We found qnr to be broadly spread over different livestock and food matrices, and to be present in various sequence types. The qnr-positive isolates were predominantly detected within selectively isolated ESBL (extended spectrum beta-lactamase)-producing E. coli, leading to a frequent association with other resistance genes, especially cephalosporin determinants. Furthermore, we found that qnr correlates with the presence of genes involved in resistance development against quaternary ammonium compounds (qac). The detection of additional point mutations in many isolates within the chromosomal QRDR region led to even higher MIC values against fluoroquinolones for the investigated E. coli. All of these attributes should be carefully taken into account in the risk assessment of qnr-carrying E. coli from livestock and food.

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