Determination of Vitamin B12 and Biotin in Foods for Special Dietary Uses with Immunoaffinity Column

2020 ◽  
Vol 35 (3) ◽  
pp. 252-260
Author(s):  
Bo-Young Oh ◽  
Min-Ji Ye ◽  
Soo-Jung Hu ◽  
Hye-Young Lee ◽  
Soo-Jin Bang
Keyword(s):  
Vitamin B ◽  
Immunoaffinity Column

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.

Determination of Ochratoxin A in Feed by Immunoaffinity Cleanup and Liquid Chromatography

2013 ◽  
Vol 96 (3) ◽  
pp. 599-602 ◽  
Author(s):  
Ping Ding ◽  
Ziyou Mi ◽  
Yali Hou ◽  
Yigang He ◽  
Jianhua Xie
Keyword(s):  
Liquid Chromatography ◽  
Detection Limit ◽  
Ochratoxin A ◽  
Cyanogen Bromide ◽  
Polyclonal Antibodies ◽  
Immunoaffinity Column ◽  
Low Levels ◽  
Sepharose 4B ◽  
Feed Samples

Abstract A method using LC was developed for determination of ochratoxin A (OTA) in feeds. The extracted samples were cleaned up by an immunoaffinity column prepared by covalently coupling polyclonal antibodies against OTA to cyanogen bromide-activated Sepharose 4B. The eluates were determined by LC with fluorescence detection. Recoveries of OTA from fortified samples of 1–10 μg/kg levels ranged from 84.3 to 90.0%, with CVs of 3.3–7.8%. The detection limit was 0.045 μg/kg based on an S/N of 3:1. A total of 65 feed samples were screened for OTA with the proposed method. The results showed that only nine samples were contaminated with OTAs at low levels. The presented method was successfully applied to quantify OTAs in real feed samples.

scholarly journals Comparison of two sample preparation procedures for HPLC determination of ochratoxin A

2009 ◽  
Vol 61 (4) ◽  
pp. 639-644 ◽  
Author(s):  
Gorica Vukovic ◽  
Snezana Pavlovic ◽  
M.S. Ristic
Keyword(s):  
Sample Preparation ◽  
Phosphoric Acid ◽  
Ochratoxin A ◽  
Chromatographic Determination ◽  
Liquid Extraction ◽  
Immunoaffinity Column ◽  
Maize Flour ◽  
Liquid Liquid Extraction ◽  
Immunoaffinity Columns

In preparation of samples for chromatographic determination of ochratoxin A, two types of columns were used for sample cleanup (SPE and immunoaffinity columns). The first method consisted of liquid-liquid extraction with a mixture of chloroform and phosphoric acid, followed by ion-exchange cleanup on Waters Oasis MAX columns. The sec?ond method consisted of extraction with a mixture of water and methanol, followed by LCTech OtaCLEAN immunoaf?finity column cleanup. Recoveries of the methods were determined at three levels in three repetitions for maize flour, and they were 84% (%RSD = 19.2) for the first method of sample preparation and 101% (%RSD = 2.2) for the second method. Values of LOQ for OTA were 0.25 and 1.00 ?g/kg for the IAC and SPE clean-up procedures, respectively. Both methods comply with present regulations, but the MAX sample clean-up procedure should be used as an alternative, since the immunoaffinity column clean-up procedure is characterized by better reproducibility, accuracy, and efficiency.

scholarly journals Determination of plasma glucose enrichment in human subjects after primed, constant infusions of 13C‐glycine before and after dietary vitamin B‐6 restriction

2009 ◽  
Vol 23 (S1) ◽  
Author(s):  
Vanessa Rodrigues Silva ◽  
Yvonne Lamers ◽  
Maria Ralat ◽  
Lesa Gilbert ◽  
Christine Keeling ◽  
...  
Keyword(s):  
Plasma Glucose ◽  
Human Subjects ◽  
Dietary Vitamin ◽  
Vitamin B ◽  
Before And After
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