ANALISIS, IDENTIFIKASI PRECURSOR DAN HASIL DEGRADASI SENYAWA SENJATA KIMIA MENGGUNAKAN TEKNIK GAS CHROMATOGRAPHY MASS SPECTROMETRY– ELECTRON IONISASI (GCMS-EI)

Abstract

Telah dilakukan analisis, identifikasi precursor dan hasil degradasi senyawa senjata kimia  diethyl methylphosphonat (DEMP), methyl phosphonic acid (MPA) dalam sampel air dan  dimethyl methyl phosphonat (DMMP), ethyl phosphonic acid (EPA) dalam sampel tanah. Contoh yang dianalisa merupakan contoh senyawa tributilphosphat  (TBP)  40 ug/mL dan poliethilene glycol  56,24 ug/mL ditambahkan sebagai background dan sampel tanah kering yang berpasir. Identifikasi dilakukan dengan  metode  kromatografi gas spektrometri massa - elektron ionisani (GCMS-EI). Ekstraksi fasa organik  pada pH netral, sililasi dari fasa air yang diuapkan,  di mana triethylamine/methanol-sililasi dan  kation exchange-sililasi digunakan untuk ekstraksi senyawa - senyawa precursor dan hasil degradasi sebelum diinjeksikan ke GCMS. Dari hasil analisis diperoleh  waktu retensi  8,9 dan 10,97  menit  masing - masing untuk  diethyl methylphosphonat dan bis(trimethylsilyl) methylphosphonate dalam sampel air sedangkan dalam sampel tanah  6,62 dan 12,06 menit untuk dimethyl methylphosphonat  dan bis(trimethylsilyl) ethylphosphonate. Total Ion Chromatography (TIC) yang dihasilkan dari GCMS dievaluasi dengan menggunakan    Library Data Base NIST (National Institute of Standards and Technology), dan AMDIS (Automated Mass Spectral Deconvolution and Identification System). Spektrum yang dihasilkan memberikan nilai base peak pada m/z = 97  untuk  diethyl methylphosphonate , m/z = 225 untuk  bis(trimethylsilyl) methylphosphonate, m/z = 94 untukdimethyl methylphosphonate dan m/z = 239 untuk bis(trimethylsilyl) ethylphosphonate sedangkan  retention index (RI) yang dihitung digunakan untuk  mengonfirmasi masing-masing senyawa precursorKata kunci : precursor, degradsi senyawa senjata kimia, base peak , waktu retensi,  Total Ion KromatografiAnalysis, precursoridentification have been done and  degradation compoundsof chemical weapon diethyl methylphosphonat , methyl phosphonic acid in water matrices, dimethyl methylphosphonat and ethyl phosphonic acidin soil samples. Water used for extracting those  compounds was an example of simulation that contain tributilphosphat  (TBP)  40 ug/mL and poliethylene glycol  56,24 ug/mL which added as a background and  dry sandy soil samples. Identification was done  by using Gas Chromatographic Mass Spectrometry – Electron Ionization (GCMS-EI) method. Neutral organic extraction, evaporated water - silylation, triethylamine/methanol-silylation and cation exchanged-silylation were performed to extract the precursor’s compounds from the samples, before being analyzed by gas chromatography mass spectrometry .The result of the analysis by  Gas Chromatographic  Mass Spectrometry  method showed that the retention time (in min) was 8,9 and 10,97 for diethyl methylphosphonat and bis(trimethylsilyl) methylphosphonate in the water sample , while the retention time in soil sample was 6,62 and  12,06 for dimethyl methylphosphonat and bis(trimethylsilyl) ethylphosphonate . The result of Total Ion Chromatography (TIC) from GCMS was evaluated using NIST (National Institute of Standards and Technology) database library and AMDIS (Automated Mass Spectral Deconvolution and Identification System). The spectrum’s result gave the value of base peak, which are m/z = 97for diethyl methylphosphonat, m/z= 225 for bis(trimethylsilyl) methylphosphonate , m/z = 94 for dimethyl methylphosphonat and m/z = 239 for bis(trimethylsilyl) ethylphosphonate. On the other hand, the retention indice (RI) calculation was used to get the confirmation of each compounds of precursors. Key word : precursor, degradation of chemical weapon,  base peak, retention time, totalion chromatography.