Determination of fluorine concentrations in soil samples using proton induced gamma-ray emission A. Srivastava • S. Chhillar • D. Singh • R. Acharya • P. K. Pujari Received: 29 August 2014 / Published online: 5 October 2014 Ó Akade ´miai Kiado ´, Budapest, Hungary 2014 Abstract A non-destructive, in situ current normalized particle induced gamma-ray emission methodology has been standardized for quantification of fluorine (F) in soil samples from Punjab state, India. The samples were irradiated using 4 MeV proton beam from the Folded Tandem Ion Accelerator at BARC, Mumbai. The gamma rays of energies 197 and 478 keV arising from 19 F(p, p 0 c) 19 F and 7 Li(p, p 0 c) 7 Li nuclear reactions were measured using high resolution gamma-ray spectrometry. The concentration of fluorine in soil samples was found to vary between 414 and 5,746 mg kg -1 . Keywords Soil  Fluorine  PIGE  Gamma-ray spectrometry  4 MeV proton beam Introduction It is a well-established fact that long exposure to fluoride could be harmful to bones and teeth. It has been estimated that in India close to 62 million people are affected by water con- taminated with fluoride. Rajni Sharma [1] has reported that the concentration of fluoride in drinking water from Amritsar, Bhatinda, Faridkot, Fatehgarh Sahib, Firozepur, Gurdaspur, Mansa, Moga, Muktsar, Patiala and Sangrur Districts of Punjab, a state located in the north western part of India between 29.5°N and 32.5°N latitude and between 73.8°E and 76.9°E longitude, is higher than the permissible level of 1.5 mg kg -1 recommended by World Health Organization [2]. Figure 1 shows the district wise map of Punjab State. The main sources of fluoride are minerals like fluorite, fluorapatite and cryolite [3] which are present deep in earth’s crust. Fluorine is also known to be present in significant amount in products of coal combustion besides pesticides and fertilizer [4]. Punjab being the foremost Indian State in agriculture production during the green revolution has been a site for indiscriminate application of pesticides and fertilizers in its soil. Therefore, it should not be surprising if soil itself could be an important source leading to the contamination of drinking water by fluoride. Rajbir Kaur et al. [5] have reported the concentration of fluorine in soil samples collected from locations in and around Chandigarh the capital city of Punjab State which so far seems to have not been affected by fluoride contaminated water. Fluorine concentration in soil is nor- mally determined by chemical separation followed by fluo- ride detection employing techniques like colorimetry, spectrophotometry or ion selective electrodes [6–8]. Saha and Kundu [9] have demonstrated that fluorine in soil can also be measured using ion chromatography. These techniques are however prone to under estimation of the actual value in the case of 100 % chemical recovery being not attained. In the present work, nuclear analytical technique namely particle induced gamma ray emission (PIGE) has been used which is independent of chemical recovery factor. PIGE is sensitive technique for low Z elements (Z \ 17) especially for lithium and fluorine [10, 11]. It finds applications in many fields including pharmaceuticals [11], glass [12], teeth [13, 14], aerosols [15] and geological and environmental reference materials [16, 17]. This makes it complementary to techniques A. Srivastava (&) Department of Chemistry, Panjab University, Chandigarh 160014, India e-mail: alok@pu.ac.in S. Chhillar  R. Acharya  P. K. Pujari Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India D. Singh Department of Soil, Punjab Agricultural University, Ludhiana 141027, India 123 J Radioanal Nucl Chem (2014) 302:1461–1464 DOI 10.1007/s10967-014-3661-5