A novel analytical method for accurate determination of boron (B), phosphorous (P), and molybdenum (Mo) content in biosludge samples based on a relatively recent analytical technique, microwave plasma atomic emission spectrometry (MP-AES), is developed in the present work. Microwave assisted acid digestion method is utilized to extract B, P, and Mo from biosludge. To demonstrate the reliability and accuracy of the present MP-AES method, its results are compared with those obtained using two well-established techniques, i.e., flame atomic absorption spectrometry (FAAS) and inductively coupled plasma optical emission spectrometry (ICP-OES). Matrix variation in the MP-AES technique is found to result in minimal changes. Precision and accuracy of the developed method are demonstrated using replicate analyses of certified sewage sludge reference material, EnviroMAT (BE-1). The limit of quantification and detection of B, P, and Mo in the extracts are determined; the linear regression coefficient was greater than 0.998 for all the three techniques. Analytical wavelengths are selected according to the sensitivity and interference effects. The results obtained in this work demonstrate the potential of MP-AES technique for the determination of B, P, and Mo content in biosludge, which achieved lower detection limits, higher accuracy, and better reproducibility as compared to other techniques.

Abstract:A new method for the separation, pre-concentration and accurate determination of trace amounts of Pb and Cd in water samples using Amberlite XAD-16 resin functionalized with a new chelating ligand, 3-(2-hydroxyphenyl)-1H-1,2,4-triazole-5(4H)-thione (HTT), Amberlite XAD-16-HTT and inductively coupled plasma atomic emission spectrometry (ICP-AES) is reported in the present study. Fourier transform infrared (FTIR) spectroscopy was used to characterize the chelating resin. The effects of analytical parameters such as the pH of the medium, amount of adsorbent, type and volume of eluent, flow rate of the sample solution, volume of the sample solution, and matrix interference on the retention of metal ions were investigated. Also, 1 M HNO 3 was used for the elution of the sorbed metals, and ICP-AES was used for the analysis of elutes offline. The results indicate that pH 5 is the optimum pH for the sorption of Pb and Cd ions. The limit of detection was found to be 0.16 and 0.22 µg/L for Pb and Cd, respectively, by applying a pre-concentration factor of 50. The method was validated using the international water reference material (NIST 1643e). The developed enrichment method has a high selectivity, sensitivity, and reproducibility; this method was successfully applied for the determination of Pb and Cd in surface water samples collected in Nellore District, Penner River belt as well as Bay of Bengal, Andhra Pradesh, India.

Recently introduced microwave plasma-atomic emission spectroscopy (MP-AES) represents yet another and very important addition to the existing array of modern instrumental analytical techniques. In this study, an attempt is made to summarize the performance characteristics of MP-AES and its potential as an analytical tool for environmental studies with some practical examples from Patancheru and Uppal industrial sectors of Hyderabad city. A range of soil, sediment, water reference materials, particulate matter, and real-life samples were chosen to evaluate the performance of this new analytical technique. Analytical wavelengths were selected considering the interference effects of other concomitant elements present in different sample solutions. The detection limits for several elements were found to be in the range from 0.05 to 5 ng/g. The trace metals analyzed in both the sectors followed the topography with more pollution in the low-lying sites. The metal contents were found to be more in ground waters than surface waters. Since a decade, the pollutants are transfered from Patancheru industrial area to Musi River. After polluting Nakkavagu and turning huge tracts of agricultural lands barren besides making people residing along the rivulet impotent and sick, industrialists of Patancheru are shifting the effluents to downstream of Musi River through an 18-km pipeline from Patancheru. Since the effluent undergoes primary treatment at Common Effluent Treatment Plant (CETP) at Patanchru and travels through pipeline and mixes with sewage, the organic effluents will be diluted. But the inorganic pollutants such as heavy and toxic metals tend to accumulate in the environmental segments near and downstreams of Musi River. The data generated by MP-AES of toxic metals like Zn, Cu, and Cr in the ground and surface waters can only be attributed to pollution from Patancheru since no other sources are available to Musi River.