Synthesis and application of alizarin complexone functionalized polyurethane foam: preconcentration/separation of metal ions from tap water and human urine.

A new chelating sorbent has been synthesized by the covalent condensation of alizarin complexone (ALC) to polyurethane foam (PUF) through -N=C- group. The material was characterized by IR, (1)H NMR and chemical proof. Iminodiacetic acid groups are found in the prepared sorbent and the reaction proceeded via condensation between the toluidine moieties in the PUF and non-hydrogen bonded carbonyl group in ALC. Also, the possibility of elimination reaction between the groups (NH(2), NH and OH) in the polymer and carboxylic groups in the reagent was excluded. The material has been used to separate/preconcentrate Cu(2+), Zn(2+) and Cd(2+) prior to their determination by flame atomic absorption spectrometry (FAAS). Chemical and flow variables such as sample pH, sorbent capacity, sample flow rate and interference from co-existing ions were investigated. All metal ions are quantitatively desorbed by 0.1 mol L(-1) nitric acid solution. The procedure provides concentration factor 100 and limits of detection 0.013 microg mL(-1). The method was validated by the analysis of certified reference materials and real samples such as tap water and human urine.

Vimentin expression in different types of breast carcinoma immunohistochemical study.

Vimentin was preferentially expressed in medullary and high grade ductal not otherwise specified (NOS) carcinomas. It was not expressed in lobular carcinoma whether of the classical or the variant types. In the present study, 58 cases of invasive breast carcinomas were tested for vimentin on formaldehyde fixed paraffin embedded sections. Vimentin was expressed in 14/ 44 (32%) of infiltrating duct carcinoma NOS. It was expressed in less than 10% of tumour cells in 5/44 (11.4%) and in > or = 10% of tumour cells in 4/7 (57%). However, none of the lobular carcinoma expressed vimentin. Vimentin was expressed in 9 of 18 (50%) of grade III infiltrating duct NOS carcinoma versus 5 of 21 (24%) of grade II and 0 of 5 (0%) of grade I carcinoma. It was preferentially expressed in tumour growing in broad anastomosing bands or sheets with numerous mitoses, high nuclear grade, scanty supportive stroma and extensive necrosis.