Single step derivatization with CF₃ enone of thiophene at ambient temperature to determine propellant grade hydrazines: a study by GC and GC-MS

Abstract

A simple, highly selective and rapid gas chromatography method (packed column with flame ionization detection) has been developed to determine hydrazine and monomethylhydrazine individually and for selective determination of hydrazine in the UH 25 mixture in organic medium. This method is based on the derivatization of hydrazine (at ambient temperature) with 1,1,1-trifluoro-4-(3-thienyl) (CF3 enone) in the absence of catalyst/buffer which leads to the formation of corresponding pyrazolidine/pyrazoline/pyrazole. The organic derivatives thus formed are then detected and their presence is confirmed by GC-MS. The GC method provides good resolution between CF3 enone and its derivatives with a total analysis time of 20 min. The concentration of CF3 enone and derivatization time are optimized to determine hydrazines in the concentration range of 0.4 mM to 0.2 M. The calibration curves based on peak areas of CF3 enone and its derivatives showed good linearity with r(2) ≈ 0.999 for the working range and the precision was found to be less than 1% for hydrazine, MMH and hydrazine in UH25. The recovery was found by the standard addition method. Under the established conditions, limits of detection were 20 μM for hydrazine, 10 μM for MMH and 20 μM for hydrazine in UH25. The tolerance limit for interfering amines was also found. The advantage of this method is the selective detection and determination of hydrazine in the UH25 mixture as 1,1-dimethylhydrazine present in UH25 cannot be derivatized with CF3 enone.

A sensitive hydrazine hydrate sensor based on a mercaptomethyl-terminated trinuclear Ni(ii) complex modified gold electrode

“…This D value is relatively high as compared to some other electrodes, 21,22,33 and almost the same as that reported at a ZnO/ CNTs/HPDB modied carbon paste electrode, which suggests a faster hydrazine diffusion at this Ni 3 modied electrode. The catalytic rate constant (k cat , M À1 s À1 ) for the electrochemical reaction between hydrazine and the redox sites of Ni 3 molecules can also be evaluated by chronoamperometry through eqn (10) as follows: 17,21…”

“…1,2 However, hydrazine is highly toxic for human health, causes liver, kidneys, and central nervous system damages. 5,6 Various methods, such as spectrophotometric determination, 4, 6-9 electrochemiluminescence, 5 gas chromatography (GC) or GC tandem mass spectrometry (GC-MS), 10 and high performance liquid chromatography (HPLC) or LC-MS methods, 11,12 have been established for the detection of hydrazine. 5,6 Various methods, such as spectrophotometric determination, 4, 6-9 electrochemiluminescence, 5 gas chromatography (GC) or GC tandem mass spectrometry (GC-MS), 10 and high performance liquid chromatography (HPLC) or LC-MS methods, 11,12 have been established for the detection of hydrazine.…”

“…3 Moreover, it has been classied as a human carcinogen by the US Environmental Protection Agency (EPA), 4 and the high solubility of hydrazine (existing as hydrazine hydrate) in water increases its concentrations for ground water contamination. 5,6 Various methods, such as spectrophotometric determination, 4,6-9 electrochemiluminescence, 5 gas chromatography (GC) or GC tandem mass spectrometry (GC-MS), 10 and high performance liquid chromatography (HPLC) or LC-MS methods, 11,12 have been established for the detection of hydrazine. Although these methods demonstrate remarkable sensitivity and repeatability, they suffer from high running costs, timeconsuming derivations, and complex separation or enrichment processes.…”

MOFs-Derived Nano-CuO Modified Electrode as a Sensor for Determination of Hydrazine Hydrate in Aqueous Medium

“…Various methods for detecting hydrazine hydrate have already been established, such as spectrophotometry, electrochemiluminescence, GC-MS, and high-performance liquid chromatography (HPLC) [5][6][7][8][9], which display excellent repeatability and sensitivity. However, they may be inconvenient due to the high-cost and time-consuming running.…”