Measurements of relative distribution constants of vaporized hydrocarbons between air and polydimethylsiloxane via capillary columns for the calculation of headspace hydrocarbon compositions

ABSTRACT Thyroglobulin fractions rich and poor in new thyroglobulin were separated by means of DEAE-cellulose chromatography of dog thyroid extracts and by zonal ultracentrifugation in a sucrose gradient of guinea pig thyroid extract incubated at low temperature. The distribution of thyroxine, triiodothyronine and 3,3′,5′-(reverse)-triiodothyronine in hydrolysates of the different fractions was estimated by radioimmunoassays. Following DEAE-cellulose chromatography there was a small but statistically significant increase in the T4/T3 ratio in thyroglobulin fractions eluted at high ionic strength - that is fractions relatively rich in stable iodine but poor in fresh thyroglobulin. There were no differences in the T4/rT3 ratios between the different fractions. The ratios between iodothyronines were almost identical in the various thyroglobulin fractions following zonal ultracentrifugation in a sucrose gradient of cold treated guinea pig thyroid extract. These findings lend no support to the possibility that a relatively high content of triiodothyronines in freshly synthesized thyroglobulin modulates the thyroid secretion towards a preferential secretion of triiodothyronine and 3,3′,5′-(reverse)-triiodothyronine at the expense of the secretion of thyroxine.

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Routine identification of four sympatric species of calanoid copepods Pseudocalanus spp. in the Atlantic Arctic using a species-specific polymerase chain reaction

Journal of Oceanological Research ◽

10.29006/1564-2291.jor-2020.48(1).4 ◽

2020 ◽

Vol 48 (1) ◽

pp. 62-72

Author(s):

E. A. Ershova

Keyword(s):

Polymerase Chain Reaction ◽

Life Cycles ◽

The Arctic ◽

Relative Distribution ◽

Chain Reaction ◽

Specific Polymerase Chain Reaction ◽

Routine Identification ◽

Polymerase Chain ◽

Species Specific ◽

Plankton Communities

Сalanoid copepods of the genus Pseudocalanus play an important role in the plankton communities of the Arctic and boreal seas, often dominating in numbers and constituting a significant proportion of the biomass of zooplankton. Despite their high presence and significance in the shelf plankton communities, species-specific studies of the biology of these are significantly hampered by extremely small morphological differences between them, especially at the juvenile stages, at which they are virtually indistinguishable. In this paper, we describe a new, routine and low-cost molecular method for identifying all Pseudocalanus species found in the Atlantic sector of the Arctic: the Arctic P. acuspes, P. minutus and the boreal P. moultoni and P. elongatus, and apply it to describe the relative distribution of these species in four locations of the Arctic and sub-Arctic. With this method, species-specific polymerase chain reaction (ssPCR), mass identification of individuals of any developmental stage, including nauplii, is possible. This method can serve as an excellent tool for studying the species-specific biology of this group, describing their life cycles, as well as monitoring changes in Arctic marine ecosystems under the influence of changing climate.

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Preparation and modification of polyhedral oligomeric silsesquioxane-containing hybrid monolithic capillary columns

Chinese Journal of Chromatography ◽

10.3724/sp.j.1123.2013.03012 ◽

2013 ◽

Vol 31 (4) ◽

pp. 322

Author(s):

Junjie OU ◽

Hui LIN ◽

Zheyi LIU ◽

Zhenbin ZHANG ◽

Jing DONG ◽

...

Keyword(s):

Polyhedral Oligomeric Silsesquioxane ◽

Capillary Columns ◽

Monolithic Capillary Columns ◽

Oligomeric Silsesquioxane

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Retention of some heterocyclic amines on mixed stationary phases containing nickel(II) Schiff base chelates

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19891530 ◽

1989 ◽

Vol 54 (6) ◽

pp. 1530-1537 ◽

Cited By ~ 10

Author(s):

Joanna Masłowska ◽

Grzegorz Bazylak

Keyword(s):

Schiff Base ◽

Stationary Phases ◽

Capillary Columns ◽

Heterocyclic Amines ◽

Complex Mixtures ◽

Amine Complexes ◽

Mixed Stationary Phases ◽

Classical Columns

Stationary phases composed of squalane and some nickel(II)-β-keto amine complexes were prepared and used for the separation of complex mixtures of pyridines. The resolution achieved on short classical columns was comparable with that obtained on capillary columns.

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Examination of the Conditions of Extraction of Toxic Organic Bases and of Methods of Their Determination. III. Extraction of Ion-Associates of Dibenz[b,f]-1,4-oxazepin

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19940582 ◽

1994 ◽

Vol 59 (3) ◽

pp. 582-588

Author(s):

Jan Souček ◽

Ladislav Belický ◽

Josef Havel

Keyword(s):

Aqueous Phase ◽

Basic Dye ◽

Organic Bases ◽

Safranine T ◽

Extraction Constants ◽

Distribution Constants

The protonation and distribution constants of dibenz[b, f]-1,4-oxazepin (CR) were measured. This substance forms stable ion-associates with Acid Red 88, extractable into chloroform. Reextraction with an aqueous phase containing basic fuchsine or safranine T brings about exchange of the CR cation for the basic dye cation. The associates so formed exhibit higher conditional extraction constants and higher molar absorptivities than the initial associates.

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Extraction of rare earth metals from trichloroacetate solutions in the presence of linear polyoxonium compounds

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19911585 ◽

1991 ◽

Vol 56 (8) ◽

pp. 1585-1592 ◽

Cited By ~ 2

Author(s):

Petr Vaňura

Keyword(s):

Rare Earth ◽

Nonionic Surfactant ◽

Separation Factor ◽

Rare Earth Metals ◽

Extraction Constants ◽

Distribution Constants ◽

Factor Α

Extraction of rare earth metals from lithium trichloroacetate solutions ( 1.20-2.88 mol l-1) with solutions of the commercial nonionic surfactant Slovafol 909 (p-nonylphenylnonaethylene glycol) in chloroform and dichloromethane was investigated. The extraction constants as well as the Slovafol 909 distribution constants were determined in the water-dichloromethane and water-chloroform systems. The lanthanide distribution ratios decrease with their atomic numbers first rather rapidly (approximately to Sm): the separation factor αSmLa = 1.54 and 1.87 in dichloromethane and in chloroform, respectively; for lanthanides with higher atomic numbers the drop is less pronounced (αLuLa = 2.42 and 2.85 in the two solvents, respectively).

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