scholarly journals Electrochemical Behaviour of Tocopherols: Possibilities of Their Simultaneous Voltammetric Detection

2021 ◽  
Vol 11 (17) ◽  
pp. 8095
Author(s):  
Granit Jashari ◽  
Gylxhane Kastrati ◽  
Lucie Korecká ◽  
Radovan Metelka ◽  
Milan Sýs ◽  
...  
Keyword(s):  
Electrochemical Behaviour ◽  
Simultaneous Detection ◽  
Lithium Perchlorate ◽  
Electrochemical Technique ◽  
Naturally Occurring ◽  
Wave Voltammetry ◽  
Working Medium ◽  
Voltammetric Detection ◽  
Medium Selection ◽  
Selection Of

An electroanalytical study for possible simultaneous detection of three naturally occurring isomers of vitamin E (α, γ, and δ-tocopherol) was performed. This research includes several optimization steps, such as selection of electrode material, composition of working medium, selection of electrochemical technique, and parameters of square-wave voltammetry (SWV), to reach a well-defined recognition of peaks. A glassy carbon electrode, 99.9% acetonitrile containing 0.1 mol L−1 lithium perchlorate, SWV at the potential step of 1 mV, potential amplitude of 25 mV, and frequency of 25 Hz were decided as the most suitable working conditions. Nevertheless, the corresponding anodic peaks were not sufficiently separated due to their overlapping. Thus, four standard evaluation methods (polynomial or linear baseline, zero base, and deconvolution) were compared, and the last-mentioned method was chosen as optimum. Similar linear ranges from 3.0 × 10−6 to 1.0 × 10−5 mol L−1 were obtained for α, γ, and δ-tocopherol, characterized by determination coefficient of 0.998, 0.985, and 0.994, quantification limits of 11.28, 2.70, and 3.67 × 10−6 mol L−1 and detection limits of 3.72, 0.89, and 1.21 × 10−6 mol L−1, respectively. A recovery from 72.0 to 128.5% for different concetration ratios of tocopherols has been achieved. This recovery range is in the accordance with values reported for liquid chromatography.

Optimization of the selection of analysis methods for the determination of naturally occurring radionuclides

Kerntechnik ◽  
2008 ◽  
Vol 73 (3) ◽  
pp. 118-121
Author(s):  
T. Heinrich ◽  
L. Funke ◽  
M. Köhler ◽  
U.-K. Schkade ◽  
F. Ullrich ◽  
...  
Keyword(s):  
Naturally Occurring ◽  
Analysis Methods ◽  
Naturally Occurring Radionuclides ◽  
Selection Of

Universal Preenrichment Broth for the Simultaneous Detection of Salmonella and Listeria in Foods

1992 ◽  
Vol 55 (4) ◽  
pp. 256-259 ◽  
Author(s):  
J. STAN BAILEY ◽  
NELSON A. COX
Keyword(s):  
Listeria Monocytogenes ◽  
Simultaneous Detection ◽  
Food Products ◽  
Naturally Occurring ◽  
Secondary Enrichment

A medium and method for preenriching food products which allow the simultaneous recovery and detection of Salmonella and Listeria are described. To prevent the pH of the medium from rapidly dropping in the presence of extraneous microorganisms found in foods, this medium, universal preenrichment (UP) broth, is highly buffered and low in carbohydrates. The medium allows sublethally injured bacteria to resuscitate and multiply to sufficiently high numbers so that highly selective, secondary enrichment media can be employed to help select the specific bacteria in question from a mixed bacterial background culture. As few as 10 heat-injured Salmonella multiplied to at least 106/ml following a 24 h enrichment in UP, even in mixtures of high levels of known competitive microflora or from naturally occurring microflora found in chicken, hot dogs, or Brie cheese. As few as 10 heat-injured Listeria monocytogenes multiplied to at least 105/ml in these same experiments. From the UP broth, secondary selective preenrichment broths which favor the growth of Salmonella or Listeria can be inoculated, and subsequent protocols for the recovery of either Salmonella or Listeria can then be followed.

Genetic engineering of crop plants: from genome to gene

1997 ◽  
Vol 33 (01) ◽  
pp. 15-33 ◽  
Author(s):  
B. P. Forster ◽  
M. A. Lee ◽  
U. Lundqvist ◽  
S. Millam ◽  
K. Vamling ◽  
...  
Keyword(s):  
Genetic Engineering ◽  
Plant Breeding ◽  
Crop Plants ◽  
Trade Routes ◽  
The Past ◽  
Naturally Occurring ◽  
New Ideas ◽  
New Varieties ◽  
Transitional Phase ◽  
Selection Of

Genetic engineering of crop plants has been in progress since the dawn of agriculture, about 10 000 years ago. For millennia the genetic make-up of our crop plants has been changed by mankind's selection of naturally occurring variants. As the trade routes were developed, novel plant types were introduced into new environments and provided more variation from which to choose. At the end of the nineteenth century an understanding of the laws of heredity was gained and plant breeding protocols were devised whereby selection became accompanied by deliberate crossing. As the knowledge of the genetic structure of crop plants improved, new ways of manipulation were invented and exploited. Indeed plant breeding became a testing bed for new ideas in genetics. For the plant breeder the techniques which were most widely employed in the past were those which aided breeding, for example techniques which speeded up the production of new varieties, but still used traditional routes of crossing and selection. This was a transitional phase between plant breeding as an art and plant breeding as a science.

scholarly journals Genetically Modified Vibrio harveyiStrains as Potential Bioindicators of Mutagenic Pollution of Marine Environments

2000 ◽  
Vol 66 (2) ◽  
pp. 599-605 ◽  
Author(s):  
Agata Czyz˙ ◽  
Jacek Jasiecki ◽  
Adam Bogdan ◽  
Hanna Szpilewska ◽  
Grzegorz We˛grzyn
Keyword(s):  
Marine Bacterium ◽  
Genetically Modified ◽  
Marine Environments ◽  
Simple Method ◽  
Naturally Occurring ◽  
Low Concentrations ◽  
Serovar Typhimurium ◽  
Wild Type Counterpart ◽  
Mutagenic Pollution ◽  
Selection Of

ABSTRACT For biodetection of mutagenic pollution of marine environments, an organism naturally occurring in these habitats should be used. We found that marine bacterium Vibrio harveyi may be an appropriate bioindicator of mutagenic pollution. For positive selection of mutants, we developed a simple method for isolation of V. harveyimutants resistant to neomycin. We constructed genetically modifiedV. harveyi strains that produce significantly more neomycin-resistant mutants upon treatment with low concentrations of mutagens than the wild-type counterpart. The sensitivity of the mutagenicity test with the V. harveyi strains is at least comparable to (if not higher than) that of the commonly used Ames test, which uses Salmonella enterica serovar Typhimurium strains. Therefore, we consider that the V. harveyi strains described in this report could be used as potential bioindicators of mutagenic pollution of marine environments.

Multiplex PCR Method for the Simultaneous Detection of Histamine-, Tyramine-, and Putrescine-Producing Lactic Acid Bacteria in Foods

2005 ◽  
Vol 68 (4) ◽  
pp. 874-878 ◽  
Author(s):  
ÁNGELA MARCOBAL ◽  
BLANCA de las RIVAS ◽  
M. VICTORIA MORENO-ARRIBAS ◽  
ROSARIO MUÑOZ
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Multiplex Pcr ◽  
Simultaneous Detection ◽  
Fermented Foods ◽  
Multiplex Pcr Assay ◽  
Pcr Method ◽  
Dna Fragment ◽  
Optimized Conditions ◽  
Selection Of

In a screening of primers, we have selected three pairs of primers for a multiplex PCR assay for the simultaneous detection of lactic acid bacteria (LAB) strains, which potentially produce histamine, tyramine, and putrescine on fermented foods. These primers were based on sequences from histidine, tyrosine, and ornithine decarboxylases from LAB. Under the optimized conditions, the assay yielded a 367-bp DNA fragment from histidine decarboxylases, a 924-bp fragment from tyrosine decarboxylases, and a 1,446-bp fragment from ornithine decarboxylases. When the DNAs of several target organisms were included in the same reaction, two or three corresponding amplicons of different sizes were observed. This assay was useful for the detection of amine-producing bacteria in control collection strains and in a LAB collection. No amplification was observed with DNA from nonproducing LAB strains. This article is the first describing a multiplex PCR approach for the simultaneous detection of potentially amine-producing LAB in foods. It can be easily incorporated into the routine screening for the accurate selection of starter LAB and in food control laboratories.

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