ABSTRACT
An immuno-separated assay for ochratoxin A detection coupled with a nano-affinity cleaning up for LC-confirmation was developed. Firstly, ochratoxin A was modified to quantum dot beads for immuno-fluorescent reporters. Secondly, Fe3O4 magnetic nanoparticles were conjugated with protein G for immuno-magnetic adsorbents. The immuno-separation of fluorescent reporters by magnetic adsorbents could be completed by ochratoxin A, so the fluorescent reporters released from the immune complex indicate a linear correlation with the concentration of ochratoxin A. Furthermore, the immuno-separated ochratoxin A can be eluted from magnetic adsorbent for LC-conformation. The optimized assay showed results as follows: the quantitative range of the immuno-separated assay was 0.03-100 ng mL-1 of ochratoxin A. The recoveries for spiked samples ranged from 78.2% to 91.4%, with the relative standard deviation (RSD) being 11.9%~15.3%. Statistical analysis indicated no significant difference between the HPLC-FLD results based on commercial affinity column and by nano-affinity cleaning up.
ABSTRACT
In the title mol-ecule, C(17)H(22)N(2)O(3), the mean plane of the terminal (C=O)OMe fragment and the indole plane form a dihedral angle of 78.94â (3)°. Inter-molecular N-Hâ¯O hydrogen bonds link the mol-ecules into chains extended along the c axis. The crystal packing exhibits π-π inter-actions, indicated by the short distance of 3.472â (2)â Å between the centroids of the five-membered heterocycles of neighbouring mol-ecules.
ABSTRACT
The title compound, C(10)H(14)N(2)O(3)·H(2)O, was synthesized by alkyl-ation of methyl 3-(1H-pyrrole-2-carboxamido)-propion-ate with ethyl bromide, followed by saponification and acidification. In the crystal structure, inter-molecular O-Hâ¯O and N-Hâ¯O hydrogen bonds link the mol-ecules, forming layers parallel to the ac plane.
ABSTRACT
The title compound, C(10)H(12)N(2)O(2), was synthesized by cyclization of 3-(1-ethyl-pyrrole-2-carboxamido)propanoic acid in the presence of polyphospho-ric acid and diphospho-rus pentoxide. In the crystal structure, adjacent mol-ecules are linked by N-Hâ¯O hydrogen bonds, forming chains extending along the b axis.
ABSTRACT
In the title compound, C(5)H(5)NO(2), the pyrrole ring and its carboxyl substituent are close to coplanar, with a dihedral angle of 11.7â (3)° between the planes. In the crystal structure, adjacent mol-ecules are linked by pairs of O-Hâ¯O hydrogen bonds to form inversion dimers. Additional N-Hâ¯O hydrogen bonds link these dimers into chains extending along the a axis.
ABSTRACT
In the crystal structure of the title compound, C(8)H(10)N(2)O(3), mol-ecules are linked by N-Hâ¯O hydrogen bonds, forming ribbons of centrosymmetric dimers extending along the c axis.
