Quantitative determination of glufosinate in biological samples by liquid chromatography with ultraviolet detection after p-nitrobenzoyl derivatization.
We have established a new HPLC method for derivatizing and quantifying glufosinate (GLUF) in human serum and urine using p-nitrobenzoyl chloride (PNBC). The p-nitrobenzoyl derivative of GLUF (PNB-GLUF) was produced quantitatively over 10 min at room temperature. PNB-GLUF possesses the property of ultraviolet (UV) light absorption with a lambda(max) of 272.8 nm, and was isolated from biological specimens by reversed-phase chromatography using Inertsil Ph-3. In experiments at a UV wavelength of 273 nm, GLUF has a quantitative detection limit of 0.005 microg/ml, and when it was added to both serum and urine to yield concentrations of 0.1-1000 microg/ml, its recovery rate was quite satisfactory: at least 93.8% in all cases. Further, the measured amounts of GLUF in 23 serum samples from patients intoxicated by ingestion of GLUF compared favorably with those obtained by fluorescence derivatization-HPLC using 9-fluorenylmethyl chloroformate (R=0.998). This technique of analysis is, in addition, applicable for Glyphosat, which possesses a chemical structure resembling that of GLUF, and it will be of great use in the determination of these two compounds.
Sensitive and rapid determination of glyphosate, glufosinate, bialaphos and metabolites by UPLC-MS/MS using a modified Quick Polar Pesticides Extraction method.
Phosphoric acid-containing amino acid pesticides, including glyphosate, glufosinate, and bialaphos, have been frequently encountered in human poisoning and suicidal cases, thus a quick and sensitive determination method for these compounds is very important. Herein we report a sensitive and rapid method for the determination of glyphosate, glufosinate, bialaphos and their metabolites, aminomethylphosphonic acid (AMPA) and 3-methylphosphinicopropionic acid (MPPA) in human blood samples. The method involves extraction using a modified Quick Polar Pesticides Extraction (QuPPe) method, cleanup with the PRiME HLB sorbents and detection with ultra performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS). The LODs were 0.02mg/L for glyphosate, glufosinate and AMPA, 0.01mg/L for bialaphos and MPPA, with the analysis time as short as ∼6min. To the best of our knowledge, the LODs are lower and the analysis time is shorter than previous reports on determination of these compounds in blood and serum samples. The method was successfully applied to the detection and quantification of glyphosate and AMPA for blood samples from real forensic cases. This extremely rapid determination method with high sensitivity is of significant importance, particularly for forensic cases where quick determination is vital.
Identification of Dihydroxy Aromatic Compounds in a Low-Temperature Pyrolysis Coal Tar by Gas Chromatography−Mass Spectrometry (GC−MS) and Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS)
Dihydroxy aromatics in coal tar undergo rapid coupling reactions with each other and with some coal-derived species during coal pyrolysis and liquefaction. However, only limited information on the structure of dihydroxy aromatics is known. In this study, Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) and gas chromatography−mass spectrometry (GC−MS) were used to characterize the dihydroxy aromatics in a low-temperature pyrolyzed coal tar and its distillate and residue fractions. Negative-ion electrospray ionization (ESI) FT-ICR MS spectra of coal-tar-derived samples had low molecular masses and narrow mass ranges. Negative-ion ESI is extremely selective for the dihydroxy aromatics present in coal tar. The O2 class species had the highest ion intensity among the species in the negative-ion FT-ICR mass spectrum for each sample. Dihydroxy compounds with an aromatic core structure of benzene, indan, biphenyl (and/or acenaphthene), and naphthalene were identified in the distillate fract...