Low-lying levels in103Rh from Coulomb excitation

Five low-lying negative parity states of¹⁰³Rh up to 1277 keV excitation energy were observed to be Coulomb excited with 2·5–4·5 MeV protons. The de-excitation gamma rays from these levels were identified in the singles spectra recorded with a 57 cc Ge(Li) detector. The level energies, branching ratios, reduced transition probabilitiesB(E2) and the multipole mixing ratios () were obtained. The 880, 1106 and 1277 keV levels have been Coulomb excited with protons for the first time. The ambiguity in theJ values for 803 and 1106 keV levels have been resolved using ²-fits, the assigned spin values are 1/2^– and 5/2^–, respectively. The-values for 474·1 and 811·2 keV transitions were obtained for the first time. The results have been discussed in the light of previously reported results.The authors wish to thank Professor I. M. Govil for his active interest at various stages of this work. One of us (DCT) acknowledges the financial support from U.G.C., New Delhi, under Faculty Improvement Programme.     

Background levels of uranium in human urine

The literature on the normal content of uranium in urine is reviewed. The reported normal concentration has declined several orders of magnitude over the years, probably due to improvements in analytical technique rather than a real change. The lowest mean values were reported with spectrometry (mean of 23 ng/l in 12 subjects) and thermal ion mass spectrometry (3.4 ng/l in 1 subject). Even spectrometry is not sufficiently sensitive at normal levels, so that techniques such as fission track analysis or mass spectrometry must be used to obtain results above the detection limit of the technique for individual samples.     

Thiosalicylic acid-immobilized Amberlite XAD-2: metal sorption behaviour and applications in estimation of metal ions by flame atomic absorption spectrometry

Thiosalicylic acid (TSA)-modified Amberlite XAD-2 (AXAD-2) was synthesized by coupling TSA with the support matrix AXAD-2 through an azo spacer. The resulting chelating resin was characterized by elemental analyses, thermogravimetric analysis (TGA) and infrared spectra. The newly designed resin quantitatively sorbs CdII, CoII, CuII, FeIII, NiII and ZnII at pH 3.5-7.0 when the flow rate is maintained between 2 and 4 ml min-1. The HCl or HNO3 (2 mol l-1) instantaneously elutes all the metal ions. The sorption capacity is 197.5, 106.9, 214.0, 66.2, 309.9 and 47.4 mumol g-1 of the resin for cadmium, cobalt, copper, iron, nickel and zinc, respectively, whereas their preconcentration factor is between 180-400. The breakthrough volume of HCl or HNO3 for elution of these metal ions was found to be 4-8 ml. The limit of detection (LOD) for CdII, CoII, CuII, FeIII, NiII and ZnII was 0.48, 0.20, 4.05, 0.98, 1.28 and 3.94 micrograms l-1, respectively, and the limit of quantification (LOQ) was found to be 0.51, 0.29, 4.49, 1.43, 1.58 and 4.46 micrograms l-1, respectively. The loading half time, t1/2, for the cations was found to be less than 2.0 min, except for nickel for which the value was 13.1 min. The determination of each of these six cations is possible in the presence of other five, if their concentration is up to 4 times. All six metals were determined in river water (RSD approximately 0.7-7.7%) and tap water samples (RSD approximately 0.3-5.7%). The estimation of Co was made in the samples of multivitamin tablets (RSD < 2.3%). The results agree with those quoted by manufacturers.     

Peptide labeling using 188Re, 188Re-MAG3 and 153Sm-H1ETA: A comparison on their in vitro lipophilicity

Lanreotide peptide was labeled with ¹⁵³Sm-H₁ETA and ¹⁸⁸Re-MAG₃ in order to evaluate whether or not their conjugation to the peptide produce significant differences of the in vitro lipophilicity with respect to the ¹⁸⁸Re-lanreotide prepared by the direct labeling method (highly lipophilic). The differences of lipophilicity between the complexes, were evaluated using a reverse phase HPLC system. The measured lipophilicity of ¹⁵³Sm-H₁ETA-lanreotide, ¹⁸⁸Re-MAG₃-lanreotide and ¹⁸⁸Re-lanreotide was taken to be the capacity factor [k" = (t _R-t ₀)/t ₀ where t _R is the retention time and t ₀ is the dead time] for each of the complexes under identical chromatography conditions. Results showed that the in vitro lipophilicity decreased in the order ¹⁸⁸Re-lanreotide (direct labeling), ¹⁸⁸Re-MAG₃-lanreotide and ¹⁵³Sm-H₁ETA-lanreotide. Since the last one has a capacity factor (k") similar to that of ¹⁸⁸Re-MAG₃, some renal elimination for ¹⁵³Sm-H₁ETA-lanreotide could be expected, which probably would reduce the unnecessary radiation dose to normal tissues.