BIOASSAY OF SEAWATER: II. METHODS FOR THE DETERMINATION OF CONCENTRATIONS OF DISSOLVED VITAMIN B1 IN SEAWATER

1966 ◽  
Vol 12 (6) ◽  
pp. 1079-1089 ◽  
Author(s):  
A. F. Carlucci ◽  
S. B. Silbernagel
Keyword(s):  
Vitamin B1 ◽  
Vitamin B ◽  
Internal Standards ◽  
Cell Counts ◽  
No Inhibition ◽  
Uptake Rates ◽  
Seawater Samples ◽  
Uptake Method

Methods for the bioassay of seawater for vitamin B1 (thiamine) using the marine chrysomonad, Monochrysis lutheri, are described. Cell counts after a 120-hour incubation or 14C-uptake rates after a 48- or 72-hour incubation were proportional to the vitamin B1 concentrations in seawater. Samples of seawater were supplemented with nutrients, filter-sterilized, and, if necessary, diluted with medium prepared in charcoal-treated seawater. External and internal standards were used. A starved culture of M. lutheri was added and the assay-flasks were incubated in the light for 46 or 70 hours, after which 14C as Na214CO3 was added and its uptake was measured after 2 hours. Cell counts were made after 120 hours. Most of the samples bioassayed to date showed no inhibition to the alga. The range of vitamin B1 concentrations which can be assayed was about 2–35 ng/l by 46-hour preincubation followed by 14C-uptake measurements or by counting cells after 120 hours. The range was extended to 100 ng B1/l after the 70-hour preincubation in the 14C-uptake method. These methods were capable of determining vitamin B1 in seawater at about one-tenth the level reported previously.

BIOASSAY OF SEAWATER: I. A 14C UPTAKE METHOD FOR THE DETERMINATION OF CONCENTRATIONS OF VITAMIN B12 IN SEAWATER

1966 ◽  
Vol 12 (1) ◽  
pp. 175-183 ◽  
Author(s):  
A. F. Carlucci ◽  
S. B. Silbernagel
Keyword(s):  
Internal Standard ◽  
Natural Seawater ◽  
Centric Diatom ◽  
Inhibitory Effects ◽  
Internal Standards ◽  
Sterile Medium ◽  
Seawater Samples ◽  
C Assimilation ◽  
Uptake Method

A method is described employing 14CO2 uptake by the marine centric diatom Cyclotella nana (clone 13-1) for the bioassay of vitamin B12 in seawater. Seawater samples were filter sterilized, supplemented with sterile medium constituents, and diluted with a similarly supplemented, charcoal-treated filtered seawater. Samples or diluted samples, internal standards, and external standards were inoculated with the diatom such that the initial concentration of cells was approximately 1 × 104 per milliliter. The bioassay flasks were incubated for 47 hours, 14C as Na214CO2 was added, and 14C assimilation was measured after a 2-hour exposure. The rate of uptake of 14C could be related to B12 concentrations when these were in the range of 0.05 to 3.0 μμg B12 per milliliter. A 49-hour incubation time was selected since cells required time to adapt to seawaters collected from different locations. The concentration of B12 in a seawater sample was calculated from the radiocarbon uptake, the percentage of the internal standard recovered, and the dilution factor. The method is more sensitive than that described by Gold from which it was derived, and takes into account the serious inhibitory effects found in many samples of natural seawater. The limit of sure detection is about 0.05 μμg B12 per ml and the standard deviation of the method was about 0.3 μμg per ml when measuring 1.4 μμg B12 per ml in inhibitory seawater.

scholarly journals ANALYSIS OF VITAMIN B-COMPLEX OF EEL FISH (ANGUILLA MARMORATA (Q.) GAIMARD) ON ELVER PHASE ORIGIN LAKE POSO

2019 ◽  
Vol 2 (2) ◽  
pp. 49
Author(s):  
Fenti Fenti ◽  
Agustinus Widodo ◽  
Jamaluddin Jamaluddin
Keyword(s):  
Liquid Chromatography ◽  
High Performance ◽  
Vitamin B1 ◽  
Nutrient Content ◽  
The Body ◽  
Vitamin B ◽  
Anguilla Marmorata ◽  
B Vitamin ◽  
Complex Organic

Background & Objective: Vitamins are complex organic substances that are needed by the body in small amounts, usually cannot be synthesized by the body but are important in metabolic processes one of which is vitamin B. Vitamin B consists of vitamins B1, B2, B3, B6, B9 and B12. Eel is one of the fish that has a high nutrient content, one of which is vitamin B. This study aims to determine the levels of vitamin B (B1, B2, B3, B6, B9 and B12) in Eel fish (Anguilla marmorata (Q.) Gaimard) on Elver phase from Lake Poso. Material and Methods: Determination of vitamin B1, B2, B3, B6 and B9 using HPLC (High Performance Liquid Chromatography), and vitamin B12 using LC-MS (Liquid Chromatography-Mass Spectrometry) . Results: The levels of vitamin B2, B3 and B12is 0.133 mg/100g, 1.895 mg/100g, and 0.017mg/100g, whereas in vitamin B1, B6 and B9 is not detected. Conclusion: Eel fish (Anguilla marmorata (Q.) Gaimard) on Elver phase from Lake Poso can be used as a source of vitamins B2, B3 and B12.

Sensitive and highly selective determination of vitamin B1 in the presence of other vitamin B complexes using functionalized gold nanoparticles as fluorophore

RSC Advances ◽  
2015 ◽  
Vol 5 (62) ◽  
pp. 49920-49925 ◽  
Author(s):  
Sekar Shankar ◽  
S. Abraham John
Keyword(s):  
Gold Nanoparticles ◽  
Detection Limit ◽  
Vitamin B1 ◽  
Vitamin B ◽  
Selective Determination ◽  
Functionalized Gold Nanoparticles ◽  
Spectrofluorimetric Determination

This work describes the spectrofluorimetric determination of thiamine in the presence of vitamin B complexes using 4-amino-6-hydroxy-2-mercaptopyrimidine as fluorophore. The detection limit was found to be 6.8 fM L−1 (S/N = 3).

Comparison of Extraction Methods for the Determination of Vitamin B1 and B3 in Foods

2020 ◽  
Vol 49 (8) ◽  
pp. 822-828
Author(s):  
Jimin Yoon ◽  
Naeun Kim ◽  
Ahyeong Jeon ◽  
Jihyun Kwon ◽  
Sang-Hoon Lee ◽  
...  
Keyword(s):  
Vitamin B1 ◽  
Extraction Methods

scholarly journals CHEMICAL DETERMINATION OF VITAMIN B1

1939 ◽  
Vol 127 (2) ◽  
pp. 531-540
Author(s):  
Daniel Melnick ◽  
Henry Field
Keyword(s):  
Vitamin B1 ◽  
Chemical Determination

scholarly journals Kinetic mechanism of Na+-coupled aspartate transport catalyzed by GltTk

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Gianluca Trinco ◽  
Valentina Arkhipova ◽  
Alisa A. Garaeva ◽  
Cedric A. J. Hutter ◽  
Markus A. Seeger ◽  
...  
Keyword(s):  
Kinetic Mechanism ◽  
Protein Quantification ◽  
Detergent Solution ◽  
Sodium Ions ◽  
Binding Studies ◽  
Equilibrium Binding ◽  
Uptake Rates ◽  
Bona Fide ◽  
Inside Out

AbstractIt is well-established that the secondary active transporters GltTk and GltPh catalyze coupled uptake of aspartate and three sodium ions, but insight in the kinetic mechanism of transport is fragmentary. Here, we systematically measured aspartate uptake rates in proteoliposomes containing purified GltTk, and derived the rate equation for a mechanism in which two sodium ions bind before and another after aspartate. Re-analysis of existing data on GltPh using this equation allowed for determination of the turnover number (0.14 s−1), without the need for error-prone protein quantification. To overcome the complication that purified transporters may adopt right-side-out or inside-out membrane orientations upon reconstitution, thereby confounding the kinetic analysis, we employed a rapid method using synthetic nanobodies to inactivate one population. Oppositely oriented GltTk proteins showed the same transport kinetics, consistent with the use of an identical gating element on both sides of the membrane. Our work underlines the value of bona fide transport experiments to reveal mechanistic features of Na+-aspartate symport that cannot be observed in detergent solution. Combined with previous pre-equilibrium binding studies, a full kinetic mechanism of structurally characterized aspartate transporters of the SLC1A family is now emerging.

scholarly journals Gas Chromatographic Determination of Traces of Accelerants in Physical Evidence

1972 ◽  
Vol 55 (4) ◽  
pp. 840-845 ◽  
Author(s):  
Charles R Midkiff ◽  
Willard D Washington
Keyword(s):  
Liquid Chromatography ◽  
Solvent Extraction ◽  
Vapor Phase ◽  
Selection Criteria ◽  
Chromatographic Determination ◽  
Operating Parameters ◽  
Gas Liquid Chromatography ◽  
Internal Standards ◽  
Physical Evidence

Techniques developed for use with gas-liquid chromatography for the examination of evidence collected at the scene of suspected arson fires and firebombings are discussed. Both solvent extraction and vapor phase examinations are employed. Internal standards are used for the identification of specific components in actual samples to allow confirmation of hydrocarbon type, e.g., gasoline and kerosene. Operating parameters and solvent selection criteria are included. Results obtained from known materials and residual hydrocarbons in actual samples are compared.

Inhibition of carbon fixation as a function of zinc uptake in natural phytoplankton assemblages

1979 ◽  
Vol 59 (4) ◽  
pp. 937-949 ◽  
Author(s):  
Anthony G. Davies ◽  
Jillian A. Sleep
Keyword(s):  
Carbon Fixation ◽  
Natural Populations ◽  
Plant Cells ◽  
Toxic Metal ◽  
Vitamin B ◽  
Phytoplankton Assemblages ◽  
Metal Contents ◽  
Rate Limiting ◽  
Natural Phytoplankton

There is now a substantial body of evidence that the growth rates of phytoplankton in culture are more closely related to the cellular levels of the rate-limiting constituent, be it a nutrient, micronutrient or toxic metal, than to the concentrations in the supporting medium; nitrate, Caperon (1968); phosphate, Fuhs (1969); silicate, Paasche (1973); vitamin B12, Droop (1968); iron, Davies (1970); mercury, Davies (1974); cadmium, Davies (1978a). This has suggested the requirement for a technique which would allow the determination of comparable relationships for natural populations of phytoplankton - how, for instance, their carbon fixation rates depend upon the metal contents of the plant cells. Although the effects of metals upon carbon fixation in phytoplankton assemblages from several different sea areas have already been examined (Knauer & Martin, 1972; Patin et al. 1974; Zingmark & Miller, 1975; Ibragim & Patin, 1976) no data seem to have been obtained on the levels of the metals present in the phytoplankton at the time of the measurements.

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