Papers by Keyword: Human Urine

Abstract: Highpurity germanium (HPGe) detector and gamma spectrometry analysis system have been used for the determination of gamma activities of radionuclides (¹³¹I, ¹³⁷Cs, ¹³⁴Cs and ⁴⁰K) in 90 human urine samples collected from residents in four provinces (Surat Thani, Nakhon Si Thammarat, Songkhla and Trang) in southern region, Thailand. Gamma radioactive standard sources (¹⁰⁹Cd, ⁵⁷Co, ¹³³Ba, ¹³⁷Cs, ⁵⁴Mn and ⁶⁰Co) were used to calibrate the detector and measurement system. Moreover, the well-known reference material ¹³¹I in human urine were also used to analyze and determine all of human urine samples. The measuring time of each sample is 10,800 seconds. It was found that, the gamma activities of ¹³¹I, ¹³⁷Cs, ¹³⁴Cs and ⁴⁰K in all samples were ranged from 0.35 7.74 Bq/d for ¹³¹I, 0.28 7.38 Bq/d for ¹³⁷Cs, 0.20 9.93 Bq/d for ¹³⁴Cs and 8.56 274.32 Bq/d for ⁴⁰K with an average values of 2.40 ± 0.78 Bq/d, 2.41 ± 0.92 Bq/d, 2.66 ± 0.84 Bq/d and 93.50 ± 30.13 Bq/d, respectively. All results showed that no statistically significant correlation with the residential area. Furthermore, the present study data could be used to be a baseline data of gamma activities in human urine of Thai people in the southern Thailand. Moreover, this new database would be not only useful in comparing and assessing an amount of gamma activities inside human body but also monitoring the exposure of radioactivity to Thai people in case of emergency of nuclear accidents around the world.

Abstract: A new method was proposed for the preconcentration/separation of zinc at trace levels using a modified organo-bentonite with dithizone (D-O-bentonite) and determined by flame atomic absorption spectrometry (FAAS). The influences of some experimental parameters including pH of the sample solution, contact time, and volume of eluent have been investigated. The influences of some matrix elements were also examined. The results show that the zinc ion could be adsorbed on the D-O-bentonite. The adsorbed quantitively was affected by the pH value of medium and contact time. In the medium of pH 4-5, the contact time was 20 min, and capacity of adsorption was 32.0 mg·g^-1. The zinc adsorbed on the sorbent could be completely eluated by using 0.5 mol·L^-1 HNO₃. The method has a good tolerance to matrix interference. The detection limit of the method for zinc ion was 0.013 µg·L^-1. The method was successfully applied to the pre-concentration/separation of zinc ion in the tap water and human urine with satisfactory results.