41 research outputs found
Electron Ionization and Atmospheric Pressure Photochemical Ionization in Gas Chromatography-Mass Spectrometry Analysis of Amino Acids
Fast Detection of Polycyclic Aromatic Hydrocarbons in Complex Mixtures of Organic Compounds Based on Gas Chromatography–Mass Spectrometry with Atmospheric Pressure Photoionization
High sensitive analysis of steroids in doping control using gas chromatography/time-of-flight mass-spectrometry
DART mass spectrometry and its applications in chemical analysis
Published data on the fundamental and applied aspects of DART mass spectrometry are surveyed. The DART ionization principles and the key parameters affect- ing the analytical characteristics of the method and the mass spectra of the determined compounds are considered. The advantages and drawbacks of DART mass spectrometry are discussed and the existing and prospective applications are outlined. The bibliography includes 120 references. © 2010 Russian Academy of Sciences and Turpion Ltd
Fast quantitation of 5-hydroxymethylfurfural in honey using planar chromatography
An approach for rapid quantitation of 5-hydroxymethylfurfural (HMF) in honey using planar chromatography is suggested for the first time. In high-performance thin-layer chromatography (HPTLC) the migration time is approximately 5 min. Detection is performed by absorbance measurement at 290 nm. Polynomial calibration in the matrix over a range of 1:80 showed correlation coefficients, r, of ≥ 0.9997 for peak areas and ≥ 0.9996 for peak heights. Repeatability in the matrix confirmed the suitability of HPTLC-UV for quantitation of HMF in honey. The relative standard deviation (RSD, %, n = 6) of HMF at 10 ng/band was 2.9% (peak height) and 5.2% (peak area); it was 0.6% and 1.0%, respectively, at 100 ng/band. Other possible detection modes, for example fluorescence measurement after post-chromatographic derivatization and mass spectrometric detection, were also evaluated and can coupling can be used as an additional tool when it is necessary to confirm the results of prior quantitation by HPTLC-UV. The confirmation is provided by monitoring the HMF sodium adduct [M + Na]+ at m/z 149 followed by quantitation in TIC or SIM mode. Detection limits for HPTLC-UV, HPTLC-MS (TIC), and HPTLC-MS (SIM) were 0.8 ng/band, 4 ng/band, and 0.9 ng/band, respectively. If 12 μL honey solution was applied to an HPTLC plate, the respective detection limits for HMF in honey corresponded to 0.6 mg kg-1. Thus, the developed method was highly suitable for quantitation of HMF in honey at the strictest regulated level of 15 mg kg-1. Comparison of HPTLC-UV detection with HPTLC-MS showed findings were comparable, with a mean deviation of 5.1 mg kg-1 for quantitation in SIM mode and 6.1 mg kg-1 for quantitation in TIC mode. The mean deviation of the HPTLC method compared with the HPLC method was 0.9 mg kg-1 HMF in honey. Re-evaluation of the same HPTLC plate after one month showed a deviation of 0.5 mg kg-1 HMF in honey. It was demonstrated that the proposed HPTLC method is an effective method for HMF quantitation in honey. [Figure not available: see fulltext.] © 2011 Springer-Verlag
Evaluation of mass spectral library search algorithms implemented in commercial software
Performance of several library search algorithms (against EI mass spectral databases) implemented in commercial software products ( acd/specdb, chemstation, gc/ms solution and ms search) was estimated. Test set contained 1000 mass spectra, which were randomly selected from NIST'08 (RepLib) mass spectral database. It was shown that composite (also known as identity) algorithm implemented in ms search (NIST) software gives statistically the best results: the correct compound occupied the first position in the list of possible candidates in 81% of cases; the correct compound was within the list of top ten candidates in 98% of cases. It was found that use of presearch option can lead to rejection of the correct answer from the list of possible candidates (therefore presearch option should not be used, if possible). Overall performance of library search algorithms was estimated using receiver operating characteristic curves
Methodological aspects of using DART mass spectrometry for fast analysis of pharmaceuticals and other complex samples
Fast quantitation of 5-hydroxymethylfurfural in honey using planar chromatography
An approach for rapid quantitation of 5-hydroxymethylfurfural (HMF) in honey using planar chromatography is suggested for the first time. In high-performance thin-layer chromatography (HPTLC) the migration time is approximately 5 min. Detection is performed by absorbance measurement at 290 nm. Polynomial calibration in the matrix over a range of 1:80 showed correlation coefficients, r, of ≥ 0.9997 for peak areas and ≥ 0.9996 for peak heights. Repeatability in the matrix confirmed the suitability of HPTLC-UV for quantitation of HMF in honey. The relative standard deviation (RSD, %, n = 6) of HMF at 10 ng/band was 2.9% (peak height) and 5.2% (peak area); it was 0.6% and 1.0%, respectively, at 100 ng/band. Other possible detection modes, for example fluorescence measurement after post-chromatographic derivatization and mass spectrometric detection, were also evaluated and can coupling can be used as an additional tool when it is necessary to confirm the results of prior quantitation by HPTLC-UV. The confirmation is provided by monitoring the HMF sodium adduct [M + Na]+ at m/z 149 followed by quantitation in TIC or SIM mode. Detection limits for HPTLC-UV, HPTLC-MS (TIC), and HPTLC-MS (SIM) were 0.8 ng/band, 4 ng/band, and 0.9 ng/band, respectively. If 12 μL honey solution was applied to an HPTLC plate, the respective detection limits for HMF in honey corresponded to 0.6 mg kg-1. Thus, the developed method was highly suitable for quantitation of HMF in honey at the strictest regulated level of 15 mg kg-1. Comparison of HPTLC-UV detection with HPTLC-MS showed findings were comparable, with a mean deviation of 5.1 mg kg-1 for quantitation in SIM mode and 6.1 mg kg-1 for quantitation in TIC mode. The mean deviation of the HPTLC method compared with the HPLC method was 0.9 mg kg-1 HMF in honey. Re-evaluation of the same HPTLC plate after one month showed a deviation of 0.5 mg kg-1 HMF in honey. It was demonstrated that the proposed HPTLC method is an effective method for HMF quantitation in honey. [Figure not available: see fulltext.] © 2011 Springer-Verlag
DART mass spectrometry and its applications in chemical analysis
Published data on the fundamental and applied aspects of DART mass spectrometry are surveyed. The DART ionization principles and the key parameters affect- ing the analytical characteristics of the method and the mass spectra of the determined compounds are considered. The advantages and drawbacks of DART mass spectrometry are discussed and the existing and prospective applications are outlined. The bibliography includes 120 references. © 2010 Russian Academy of Sciences and Turpion Ltd