Synthesis of meso-tetra-(2-chloro-4-sulfophenyl) prophyrin and spectrophotometric determination of trace amounts of cadmium
Synthesis of a new high sensitive water soluble chromogenic reagent meso-tetra-(2-chloro-4-sulfophenyl) prophyrin and the conditions for the reaction of this reagent with cadmium (I) were studied. The apparent molar absorption coefficient at 434 nm is 5.20×105 L·mol−1·cm−1. The method has been applied to the determination of 5.0×10−9 (content by weight) Cadmium (I) in honey.
Abnormalities occurring during female gametophyte development result in the diversity of abnormal embryo sacs and leads to abnormal fertilization in indica/japonica hybrids in rice.
Embryo sac abortion is one of the major reasons for sterility in indica/japonica hybrids in rice. To clarify the causal mechanism of embryo sac abortion, we studied the female gametophyte development in two indica/japonica hybrids via an eosin B staining procedure for embryo sac scanning using confocal laser scanning microscope. Different types of abnormalities occurred during megasporogenesis and megagametogenesis were demonstrated. The earliest abnormality was observed in the megasporocyte. A lot of the chalazal-most megaspores were degenerated before the mono-nucleate embryo sac stage. Disordered positioning of nucleus and abnormal nucellus tissue were characteristics of the abnormal female gametes from the mono-nucleate to four-nucleate embryo sac stages. The abnormalities that occurred from the early stage of the eight-nucleate embryo sac development to the mature embryo sac stage were characterized by smaller sizes and wrinkled antipodals. Asynchronous nuclear migration, abnormal positioning of nucleus, and degeneration of egg apparatus were also found at the eight-nucleate embryo sac stage. The abnormalities that occurred during female gametophyte development resulted in five major types of abnormal embryo sacs. These abnormal embryo sacs led to abnormal fertilization. Hand pollination using normal pollens on the spikelets during anthesis showed that normal pollens could not exclude the effect of abnormal embryo sac on seed setting.
Analytical application of porphyrins—I Spectrophotometric determination of ultramicro amounts of copper with α,β,γ,δ-tetra-(3-N-methylpyridyl)porphine
Abstract A new water-soluble porphyrin, α,β,γ,δ-tetra(3-N-methylpyridyl)porphine [T(3-MPy)P], has been synthesized, and its reaction with copper(II) studied spectrophotometrically. Sensitive methods for the determination of copper at ppM level have been established. The spectrophotometric sensitivity and relative standard deviation of the recommended procedure for copper are 0.18 ng/cm2 (for A = 0.001) and 1.0%, respectively. The interference of 19 ions and 20 salts has been examined, and found to be minimal. The methods established could be applied to the determination of copper in water samples with satisfactory results.