ABSTRACT
The title compound, C9H10N2O4, crystallizes with a disordered nitro group in twinned crystals. Both the meth-oxy group and the acetamide groups are nearly coplanar with the phenyl ring, and the C-N-C-O torsion angle [0.2â (4)°] is also insignificantly different from zero. Overall, the 12-atom meth-oxy-phenyl-acetamide group is nearly planar, with an r.m.s. deviation of 0.042â Å. The nitro group is twisted out of this plane by about 30°, disordered into two orientations with opposite senses of twist. In the crystal, the N-H group donates a hydrogen bond to a nitro oxygen atom, generating chains propagating in the [101] direction. The amide carbonyl oxygen atom is not involved in the hydrogen bonding.
ABSTRACT
In the title compound, C10H11N3O6, the torsion angles about the bonds to the benzene ring are less than 4°, except for the nitro groups, which are twisted out of the ring plane by 25.27â (3) and 43.63â (2)°. The N-H group forms a bifurcated hydrogen bond, with an intra-molecular component to a nitro group O atom and an inter-molecular component to the other nitro group, thereby forming chains propagating in the [010] direction. Several weak C-Hâ¯O inter-actions are also present.
ABSTRACT
We have developed a simple, reversed-phase high-performance liquid chromatography (RP-HPLC) method for the determination of bisphenol A (BPA) in thermal paper cash register receipts (CRs). The method is suitable for analysis of other types of bisphenols and it involves an overnight extraction of CRs with acetonitrile (AN) at 50 °C followed by the HPLC analysis on a Supelcosil LC18 column (150 × 4.6 mm, particle size: 5 µ) using 50% AN in water as the mobile phase (5 min, isocratic). The composition of AN in the mobile phase changed to 100% over a 10 min period (linear gradient) and then held at 100% AN for 10 min (isocratic). The flow rate was set at 1 mL/min (injection volume: 20 µL) and the eluent was monitored at 234 nm. The authentic BPA eluted with a retention time of 5.9 min and gave a linear detector response in the concentration range of 0.23-50 mg/L. BPA in the CR extracts also eluted with the same retention and had identical absorbance properties as the standard. When CR extracts were co-injected with authentic BPA, they were resolved as a single peak. Further, GC/MS/EI analysis of authentic BPA and the HPLC-purified CR extracts have identical ion chromatograms and fragmentation of the molecular ion (m/z = 228). We have analyzed 170 CRs collected from 62 different vendors including supermarkets, fast food restaurants, gas stations and banking outlets. Almost all cash receipts (n = 168) showed the presence of BPA in the concentration range of 0.45-4.26% (M ± SD, 1.54 ± 0.73%).