In the title compound, C(10)H(13)O(4)N(2) (+)·NO(3) (-), the nitro group and the benzene ring are essentially coplanar. The dihedral angle between the benzene ring and the methyl-carboxyl-ate plane is 49.6 (3)°. The crystal structure is stabilized by cation-anion N-H⋯O and N-H⋯N hydrogen bonds, building sheets parallel to (001).

V4444 Sgr (Nova Sgr 1999) has been recently suggested to be a possible recurrent nova based on the detection of the preexisting dust, which may have been formed in a previous outburst. We examined this possibility using the available outburst observations, including the VSNET observations. We also noticed that this nova was recorded in the OGLE II public photometric database, which covered both...

One of the ultimate goals of ion chromatography is to determine both anions and cations found in samples with a single chromatographic run. In the present article, recent progress in ion-exclusion/ion-exchange chromatography for the simultaneous determinations of inorganic anions and cations are reviewed. Firstly, the principle and the control for the simultaneous separation and detection of ...