Radiation Measurements 40 (2005) 65 – 68 www.elsevier.com/locate/radmeas
EPR of some irradiated renal stones R. Köseoˇglua , E. Köseoˇglub , F. Köksalc,∗ , E. Ba¸sarand , D. Demircie a Erciyes University, Halil Bayraktar Health Services Vocational College, Turkey b Erciyes University, Faculty of Medicine, Neurology Department, Kayseri, Turkey c Ondokuz Mayıs University, Faculty of Arts and Sciences, Physics Department, Samsun, Turkey d High Technology Institute, Physics Department, Gebze, Turkey e Erciyes University, Faculty of Medicine, Urology Department, Kayseri, Turkey
Received 2 July 2003; received in revised form 1 December 2004; accepted 15 December 2004
Abstract Some renal stones were investigated by electron paramagnetic resonance of their untreated, UV-photolyzed and gammairradiated states. Powder X-ray diffraction technique indicated that the renal stones were made mainly from CaC2 O4 , MgC2 O4 , MgCO3 and NH4 MgPO4 · 6H2 O. Before radiation treatment, the renal stones yielded a signal that could be attributed to a ˙ 2 O− radical. UV-photolysis seems to slightly increase the intensity of this signal, but does not produce any new centres. C 4 ˙ − radicals, and while the intensity of the .CH2 C(CH ˙ ˙ Gamma-irradiation initially gives .CH2 C(CH 3 ).R and CO 3 ).R signal 2 − ˙ signal increases as time elapses. decreases, the intensity of the CO 2 © 2004 Elsevier Ltd. All rights reserved. Keywords: EPR; Gamma irradiation; Renal stone; Radical
1. Introduction It is well known that when materials are exposed to highenergy radiation, some paramagnetic centres are induced and these centres can be investigated by electron paramagnetic resonance (EPR). Various kinds of stones were gammairradiated and investigated with this technique (Ikeya et al., 1993). Some biocarbonates, aragonitic shells and corals indicated the presence of the isopropyl radical (Kai and Miki, ˙ − and CO ˙ − radicals (Callens et al., 1987; Bac1989) and CO 3 2 quet et al., 1981; Ishii and Ikeya, 1993) were also observed. These radicals were found either in the natural states of the samples as impurities or as a result of gamma-irradiation. An early study on gamma-irradiated aluminium, ammonium, calcium, cadmium, lithium and magnesium oxalate
˙ − radicals (Atkins et powders indicated the presence of CO 2 al., 1962). On the other hand, some gamma-irradiated ox˙ 2 O− alate containing materials exhibited the existence of C 4 − ˙ and CO 2 radicals (Horvath et al., 1988, 1991; Ravi Kumar and Lingam, 1990). Thermal decomposition of strontium ox˙ − radicals in the decomalate indicated the presence of CO 2 position process (Angelov et al., 1986). Since the oxalates are among the contents of renal stones, we thought it interesting to study some renal stones with EPR. We have not noticed any EPR study on these materials. Therefore, it is the purpose of this study to investigate some renal stones in their untreated, UV-photolyzed and gamma-irradiated states.
2. Experimental ∗ Corresponding author. Tel.: +90 362 457 6021; +90 362 457 6081. E-mail address:
[email protected] (F. Köksal).
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The renal stones were obtained from the medicine faculties of Samsun and Erciyes Universities. The samples were powdered and exposed to UV-rays directly in the
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R. Köseoˇglu et al. / Radiation Measurements 40 (2005) 65 – 68
EPR cavity by a Conrad Hannovia 1 kW xenon lamp. The gamma-irradiations were made by a 60 Co gamma-ray source to a dosage around 5 kGy. The spectra were recorded with a Varian E-109 C model X-band EPR spectrometer using 2 mW microwave power and 100 kHz modulation frequency with an amplitude of 0.1 mT. The g factors were found by comparison with a diphenylpicrylhydrazyl sample of g = 2.0036. For the identification of the contents of renal stones, their powder X-ray diffraction spectrograms were obtained at the High Technology Institute at Gebze with a Rigaku dmask 2200 powder X-ray diffractometer. The simulation of the EPR spectra was made by using the Bruker Win EPR programme. The EPR spectra of renal stones of ten patients exhibited essentially the same behaviour in their clean, photolyzed and gamma-irradiated states.
EPR powder spectra of the renal stones exhibit a line as in Fig. 2 with g=2.0038 and a linewidth around 1 mT. The UVphotolysis for 2 h at ambient temperature seems to slightly increase the intensity of this line, which can be attributed to
3. Results and discussion X-ray powder diffraction spectrograms of renal stones indicate that they contain mainly Ca, Mg oxalates, ammonium magnesium phosphates, magnesium carbonates, etc. as shown in the two examples in Fig. 1. The common component seems to be oxalate.
Fig. 2. EPR spectrum of clean renal stones.
Intensity [cps]
500 400 300 200 100 0
20.000
40.000
60.000
2θ
Peak Data
a)
20-0231
Ca C2 04.H2 0 Whewellite. Syn
*
15-0752
N H Mg P04 .6 H 0 4 2 Struvite. Syn
*
Intensity [cps]
4000 3000 2000 1000 0
10.000
20.000
30.000
40.000
50.000
2θ
Peak Data
b)
20-0669
Mg C 03 H2 0 Nesquehonite. Syn
23-1325
KCN.KNH 2 Potassium Cyanide Amide
44-0782
H P0 3 4 Hydrogen Phosphate
28-0625
MgC204.2H20 Glushinskite. Syn
*
I
Fig. 1. X-ray powder diffraction spectrograms of renal stones of two patients (a) and (b).
R. Köseoˇglu et al. / Radiation Measurements 40 (2005) 65 – 68
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Fig. 3. (a) EPR spectrum of a gamma-irradiated renal stone. (b) ˙ Simulation of the .CH2 C(CH 3 ).R radical.
the C˙ 2 O− 4 radical, and its g value is in accord with the previously reported value of 2.0036 (Horvath et al., 1988, 1991). After gamma-irradiation, the samples yield the spectrum shown in Fig. 3. This spectrum consists of six lines. The g value of these six lines corresponds to 2.0031. This species ˙ can be attributed to the .CH2 C(CH 3 ).R radical. The hyperfine constants of the protons in the CH3 and CH2 groups (1,2,3) = 2.3 mT for the CH3 group and are thought to be a (1)
(2)
a = 2.1 mT, a = 1.9 mT for the CH2 group. Simulation of the spectrum using these constants and H = 0.24 mT in the Win EPR programme is shown in Fig. 3. These values of the hyperfine constants are similar to values in the literature (Ranby and Rabek, 1977). Furthermore, the shoulder between the third and fourth lines in Fig. 3, marked as A, grows as time elapses and at around 1 week, the spectrum becomes as shown in Fig. 4. However, when the samples are stored in liquid nitrogen, the signals do not vary discernibly even in 2 months. Kai and Miki’s studies on some gammairradiated calcified fossils of coral, mollusc shells and bone (Kai and Miki, 1989) indicated the presence of some organic radicals. They have also observed organic radicals in X-ray irradiated L-valine-doped CaCO3 samples. The spectrum in Fig. 4 can be interpreted in terms of ˙ − radical. The g values of the CO ˙ − radical are the CO 2 2 g = 1.9973 and g⊥ = 2.0025. With these parameters, the simulation of the spectrum is in good agreement with the experimental result as shown in Fig. 4. These values are in agreement with those in the literature (Ikeya et al., 1993; Ishchenko et al., 2002).
Fig. 4. EPR spectrum of a gamma-irradiated renal stone after 6 days (top: experimental, bottom: simulation).
Considering the XRD results of the renal stones in this study, one can expect a large variety among the spectra, but this is not the case here and more than ten different samples exhibited the same spectra initially; however, the lifetimes of the signals differ, some live longer than the others. In some samples, shoulder A in Fig. 3 becomes bigger than the others as time elapses and the main signal decays more quickly. Presumably, this indicates that the original chemical structures exist in all the renal stones studied; however, the environments are different and due to this environmental difference, the lifetimes of the signals differ. Finally, we point out that after around a year, the signals become similar to those of unirradiated renal stones.
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4. Conclusions This investigation shows that the untreated and photolyzed renal stones contain the C˙ 2 O− 4 radical. The gamma-irradiated renal stones indicated the inducement of ˙ − radicals. The .CH2 C(CH ˙ ˙ .CH2 C(CH 3 ).R and CO 3 ).R 2 radicals are likely to be found due to the presence of some organic amino acids. The new EPR signals produced by gamma-irradiation decay in a year.
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