Comparative quantitation of abscisic acid in plant extracts by gas-liquid chromatography and an enzyme-linked immunosorbent assay using the avidin-biotin system

Planta ◽  
1985 ◽  
Vol 166 (4) ◽  
pp. 524-529 ◽  
Author(s):  
B. Leroux ◽  
R. Maldiney ◽  
E. Miginiac ◽  
L. Sossountzov ◽  
B. Sotta

Planta ◽  
1971 ◽  
Vol 96 (4) ◽  
pp. 271-280 ◽  
Author(s):  
J. R. Lenton ◽  
V. M. Perry ◽  
P. F. Saunders


1994 ◽  
Vol 77 (5) ◽  
pp. 1275-1287 ◽  
Author(s):  
Petra M Krämer ◽  
Qing X Li ◽  
Bruce D Hammock

Abstract The integration of liquid chromatography (LC) with immunochemical detection combines the superior separation power of LC and the sensitivity and specificity of immunoassays. This approach is shown with 3 LC systems (Perkin-Elmer, C18 RP, 4.6 mm; Varian, C18 RP, 1 mm microbore; Michrom, C18 RP, 1 mm microbore) Integrated with an enzyme-linked immunosorbent assay (ELISA) selective for five 4-nitrophenols. The nitrophenols were separated with the 3 LC systems with isocratic runs of 15 to 20 min. Microbore LC separation showed a 10-20 times reduction in solvent amount compared to conventional separation. LC–immunoassay was about 8- to 10-fold more sensitive compared with LC with UV detection. Integrated LC–immunoassay proved to be a very selective method when 2-methylphenol was injected with an equimolar mixture of 2-amino-4-nitrophenol and 3-methyl-4-nrtrophenol; 2-methy I phenol does not crossreact with the serum used. Only 2 peaks could be seen in the detection, even when 2-methylphenol was present in very high amounts (3000 pmol). Further, the EUSA-LC detection proved to be selective and sensitive for complex matrixes. 2-Amlno-4-nitrophenol was clearly identified in spiked extracts of soil and plant, even when a very small amount (2.4 ng) was injected. Although LC–immunoassay is more labor intensive than LC with UV detection, it offers great advantages in multiresidue analysis and is generally applicable for peak confirmation.



1979 ◽  
Vol 57 (5) ◽  
pp. 534-538 ◽  
Author(s):  
Joe E. Webber ◽  
Murray L. Laver ◽  
Joe B. Zaerr ◽  
Denis P. Lavender

The occurrence of abscisic acid (ABA) in the dormant shoots of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) was confirmed by bioassay, thin-layer chromatography, gas–liquid chromatography, and gas–liquid chromatography – mass spectrometry. Seasonal variation of ABA in the buds, leaves, and stems was then determined using 2-trans-ABA as an internal standard. Concentrations of ABA were highest in the autumn for buds (2.1 μg/g) and needles (0.79 μg/g) and highest in January for stems (0.34 μg/g). The lowest concentrations for all tissues were in February and March, before bud burst. Close correlation of levels of ABA with previously measured physiological evidence of growth and metabolic activity suggests a possible role in the dormancy cycle of Douglas-fir.



1990 ◽  
Vol 73 (3) ◽  
pp. 451-456 ◽  
Author(s):  
Fun S Chu ◽  
Xuan Huang ◽  
R D Wei

Abstract A direct competitive enzyme-linked immunosorbent assay (ELISA) for the freshwater blue-green algal toxin mlcrocystln (MCYST) In algae and water was developed. The assay Involves coating antl-MCYST-variant leuclne-arglnine (LR) antibody to the ELISA plate and the use of MCYST-LRperoxidase as the enzyme marker. The linear portion of the standard curve for MCYST in phosphate buffer containing saline (PBS) was 0.5-10.0 ng/mL (25-500 pg/assay). The minimum detection level for MCYST-LR was 0.20 ng/mL (10 pg/assay). Contaminated water could be directly used In the ELISA. The overall analytical recoveries for MCYST-LR added to water at levels of 1-20 ng/mL was 83.4%. For analysis of cellular MCYST, the toxin was first extracted from the algae with 0.1M ammonium bicarbonate, diluted with PBS to less than 0.5 mg dried algae/mL (<5.0 mg wet welght/mL) and directly used in the ELISA. C-18 reverse-phase Sep-Pak cartridges effectively adsorbed MCYST from the toxln-containlng solutions. The toxin could be recovered from the cartridge by elutlng with 60% methanol. Using this approach, an algae extract that was relatively free of MCYST was prepared and was used in a recovery study. The overall analytical recovery of MCYST added to the algae extract In the range of 0.25-20 ppm was 83% with a coefficient of variation of 11.9%. The detection limit for MCYST In dried algae was about 0.25-0.5 pg/g (0.25-0.5 ppm) lyophlllzed algae sample. This method was applied for the analysis of several naturally occurring algal blooms. Limited samples were also analyzed for MYCST by liquid chromatography. ELISA data were in general agreement with those obtainedby liquid chromatography. MCYST concentrations from 0.006 to 2.9 fig/g (6 to 2900 ppb) and from 26 to 5200 /ig/g (26 ppm to 5200 ppm) were found In water and algae (dried weight), respectively



1987 ◽  
Vol 17 (5) ◽  
pp. 383-387 ◽  
Author(s):  
Pasi Puttonen

Spring-lifted seedlings were grown in pots in the field and, after a natural fall photoperiod, exposed to three 25-day cold (+4 °C) storage treatments and two lifting times, mid-November and mid-January. The storage treatments were light storage in pots, dark storage in pots, and bareroot storage in polyethylene bags in the dark. In a second experiment, an extended fall photoperiod treatment was applied to seedlings that were then stored in pots and subjected to the same light and dark treatments above. In both experiments, needle samples were taken four times during and after the treatments for abscisic acid assay. Abscisic acid concentrations were determined using gas liquid chromatography after purification with high performance liquid chromatography. Lifting times and storage treatments did not result in statistically significant differences in abscisic acid concentrations. However, there were treatment differences in characteristics of postplanting performance. Mid-November lifting resulted in reduced survival and a greater number of days to bud flush compared with the mid-January lifting results. The extended fall photoperiod material produced similar results to the natural fall photoperiod material. The failure to detect a relationship between needle abscisic acid concentration and seedling vigor may have been due to a transitory role of abscisic acid in the storage conditions studied. The quantification method for abscisic acid is insensitive and laborious for practical seedling testing.



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