ANALISIS, IDENTIFIKASI PRECURSOR DAN HASIL DEGRADASI SENYAWA SENJATA KIMIA MENGGUNAKAN TEKNIK GAS CHROMATOGRAPHY MASS SPECTROMETRY– ELECTRON IONISASI (GCMS-EI) - Evita Boes (Research Center for Chemistry - LIPI, 2014)
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.