• NAJAM UL RAFI

It has been found that naturally arsenic exists in many different chemical forms. These forms exist in mainly four oxidation states (As3+, As5+, As0 and As3–) which exist in organic and inorganic forms. Organic form of arsenic exist as alkyl derivative of arsenic like mono methyl arsenic acid (MMA) and dimethyl arsenic acid (DMA). Soluble forms of arsenic are separated easily by capillary electrophoresis (CE) and high pressure liquid chromatography (HPLC) methods. High pressure liquid chromatography (HPLC) method has more advantage over capillary electrophoresis (CE) because of different mechanism of mobile and stationary phases. For detection of trace elements like As , those techniques are required which are highly sensitive and selective. These techniques are nuclear magnetic resonance (NMR), X-beam photoelectron spectroscopy (XPS), electron spectroscopy for concoction examination (ESCA), X-beam assimilation fine structure spectroscopy (XAFS), electron turn reverberation (ESR), couple mass spectroscopy (TMS) and Mossbauer spectroscopy. Now the sampling problems like loss of analyte or contamination have been understood and solved. These problems with arsenic speciation become more complex and with different forms of arsenic, it has become a long time study. Preservatives have a great significance in maintaining total arsenic content in the samples. Arsenic speciation in a particular water sample cannot be done without maintaining total arsenic content specially in inorganic forms of arsenic As(lll) and As (V) .

nuclear magnetic resonance (NMR), X-beam photoelectron spectroscopy (XPS), electron spectroscopy for concoction examination (ESCA), X-beam assimilation fine structure spectroscopy (XAFS), electron turn reverberation (ESR), couple mass spectroscopy (TMS) and Mossbauer spectroscopy

"Speciation and detection of arsenic in Groundwater samples: A Review of various analytical methods", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.6, Issue 11, page no.848-852, November-2019, Available :http://www.jetir.org/papers/JETIR1912113.pdf

"Speciation and detection of arsenic in Groundwater samples: A Review of various analytical methods", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.6, Issue 11, page no. pp848-852, November-2019, Available at : http://www.jetir.org/papers/JETIR1912113.pdf