Liquid chromatography-mass metabolites

Hummel D, Loffler D, Fink G, Temes TA (2006) Simultaneous determination of psychoactive drugs and their metabolites in aqueous matrices by liquid chromatography mass spectrometry. Environ Sci Technol 40 7321-7328... 

Figure 5.54 Structures of Praziquantel and its metabolites, cis- and fraw5-4-hydroxy-praziquantel. Reprinted from 7. Chromatogr., B, 708, Lerch, C. and Blaschke, G., Investigation of the stereoselective metabolism of Praziquantel after incubation with rat liver microsomes by capillary electrophoresis and liquid chromatography-mass spectrometry , 267-275, Copyright (1998), with permission from Elsevier Science.

Several methods can be used for the residue analysis of anilides, especially gas chro-matography/mass spectrometry (GC/MS) and liquid chromatography/mass spectrometry (LC/MS). GC/ECD or GC/NPD for the determination of anilides has generally been used except for the unstable metabolites of naproanilide and clomeprop, which are determined by HPLC/UV, HPLC/FL or GC/ECD after derivatization. 

The method for chloroacetanilide soil metabolites in water determines concentrations of ethanesulfonic acid (ESA) and oxanilic acid (OXA) metabolites of alachlor, acetochlor, and metolachlor in surface water and groundwater samples by direct aqueous injection LC/MS/MS. After injection, compounds are separated by reversed-phase HPLC and introduced into the mass spectrometer with a TurboIonSpray atmospheric pressure ionization (API) interface. Using direct aqueous injection without prior SPE and/or concentration minimizes losses and greatly simplifies the analytical procedure. Standard addition experiments can be used to check for matrix effects. With multiple-reaction monitoring in the negative electrospray ionization mode, LC/MS/MS provides superior specificity and sensitivity compared with conventional liquid chromatography/mass spectrometry (LC/MS) or liquid chromatography/ultraviolet detection (LC/UV), and the need for a confirmatory method is eliminated. In summary,... 

LC/MS/MS. LC/MS/MS is used for separation and quantitation of the metabolites. Using multiple reaction monitoring (MRM) in the negative ion electrospray ionization (ESI) mode, LC/MS/MS gives superior specificity and sensitivity to conventional liquid chromatography/mass spectrometry (LC/MS) techniques. The improved specificity eliminates interferences typically found in LC/MS or liquid chro-matography/ultraviolet (LC/UV) analyses. Data acquisition is accomplished with a data system that provides complete instmment control of the mass spectrometer. 

More recently, liquid chromatography/mass spectrometry (LC/MS) and liquid chromatography/tandem mass spectrometry (LC/MS/MS) have been evaluated as possible alternative methods for carfentrazone-ethyl compounds in crop matrices. The LC/MS methods allow the chemical derivatization step for the acid metabolites to be avoided, reducing the analysis time. These new methods provide excellent sensitivity and method recovery for carfentrazone-ethyl. However, the final sample extracts, after being cleaned up extensively using three SPE cartridges, still exhibited ionization suppression due to the matrix background for the acid metabolites. Acceptable method recoveries (70-120%) of carfentrazone-ethyl metabolites have not yet been obtained. 

MAE in conjunction with high-performance liquid chromatography/mass spectrometry (HPLC/MS) shortened the cleanup procedure and provided satisfactory recoveries (97-102%) for the parent imazethapyr and its two metabolites (hydroxy and glucose conjugate metabolites). 

Ethylenethiourea (ETU) is a toxic decomposition product/metabolite of alky-lenebis(dithiocarbamates). This compound could be generated during processing of treated crops at elevated temperature. Different chromatographic methods to determine the residue levels of ETU have been published. After extraction with methanol, clean-up on a Gas-Chrom S/alumina column and derivatization (alkylation) with bro-mobutane, ETU residues can be determined by GC with a flame photometric detector in the sulfur mode. Alternatively, ETU residues can also be determined by an HPLC method with UV detection at 240 nm or by liquid chromatography/mass spectrometry (LC/MS) or liquid chromatography/tandem mass spectrometry (LC/MS/MS) (molecular ion m/z 103). ... 

Several determination methods such as GC, HPLC, gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/mass spectrometry (LC/MS) are used for the analysis of neonicotinoid residues. The applications of GC/MS and LC/MS are of increasing importance. The application of HPLC to the determination of neonicotinoids residues is limited, especially when metabolites (such as acetamiprid and nitenpyram) can be easily determined by GC after derivatization. 

Bruno F, Curini A, Di Corcia A, Fochi I, Nazzari M, Samperi R (2002) Determination of surfactants and some of their metabolites in untreated and anaerobically digested sewage sludge by subcritical water extraction followed by liquid chromatography-mass spectrometry. Environ Sci Technol 36 4156—4161... 

High performance liquid chromatography-mass spectrometric methods Nitin et al. [75] developed and validated a sensitive and selective liquid chromatography-tandem mass spectrometric method (LC MS MS) for the simultaneous estimation of bulaquine and its metabolites primaquine in monkey plasma. The mobile phase consisted of acetonitrile ammonium acetate buffer (20 mM, pH 6) (50 50, v/v) at a flow rate of 1 mL/min. The chromatographic separations were achieved on two Spheri cyano columns (5 pm, 30 cm x 4.6 mm), connected in... 

Reversed phase liquid chromatography-mass spectrometry was applied to extracts of Jamaica Bay (New York) water to determine 1-300 xg/l amounts of nonyl phenol ethoxylates and their metabolites [213]. 

Niederlander H.A.G. et al., 2006. High throughtput therapeutic drug monitoring of clozapine and metabolites in serum by online coupling of solid phase extraction with liquid chromatography-mass spectrometry. J Chromatogr B 834 98. 

C. Soler, B. Hamilton, A. Furey, K. J. James, J. Manes, and Y. Pico. Comparison of Four Mass Analyzers for Determining Carbosulfan and Its Metabolites in Citrus by Liquid Chromatography/Mass Spectrometry. Rapid Commun. Mass Spectrom., 20(2006) 2151-2164. 

Supercritical fluid extraction followed by high-performance liquid chromatography-mass spectrometry has been used to determine Atrazine and its metabolites in soil [22],... 

H.Fr. Schroder, Determination of Fluorinated Surfactants and their Metabolites in Sewage Sludge Samples by Liquid Chromatography-Mass Spectrometry and -Tandem Mass Spectrometry after Pressurised Solvent Extraction and Separation on Fluorine Modified RP-Phases, J. Chromatogr. A, in press. 

Marcomini et al. [42] studied the aerobic biodegradation mechanisms of different commercial AE blends (linear, oxo- and multibranched alkyl chains) by analysing the metabolites under the same standardised conditions applying liquid chromatography mass spectrometry LC-MS. 

B. Luo, K. Groenke, R. Takors, C. Wandrey, and M. Oldiges, Simultaneous determination of multiple intracellular metabolites in glycolysis, pentose phosphate pathway and tricarboxylic acid cycle by liquid chromatography mass spectrometry. J. Chromatogr. A 1147, 153 164 (2007). 

W. Potts, R. van Horn, K. Anderson, T. Blake, E. Garver, G. Joseph, G. Dreyer, A. Shu, R. Heys, K. L. Fong, Characterization of the Metabolites of the Peptidomimetic Human Immunodeficiency Virus Type 1 Protease Inhibitor SK F 107461 in Rats Using Liquid Chromatography/Mass Spectrometry , Drug Metab. Dispos. 1995, 23, 799 - 805. 

Huang LF, Guo FQ, Liang YZ, Li BY, Cheng BM. 2004. Simultaneous determination of L-arginine and its mono-and demethylated metabolites in human plasma by high-performance liquid chromatography-mass spectrometry. Anal Bioanal Chem 380 643. 

Kratzsch C, Peters FT, Kraemer T, Weber AA, Maurer HH. 2003. Screening, library-assisted identification and validated quantification of fifteen neuroleptics and three of their metabolites in plasma by liquid chromatography/ mass spectrometry with atmospheric pressure chemical ionization. J Mass Spectrom 38 283. 

Miki A, Tatsuno M, Katagi M, Nishikawa M, Tsuchihashi H. 2002. Simultaneous determination of eleven benzodiazepine hypnotics and eleven relevant metabolites in urine by column-switching liquid chromatography-mass spectrometry. J Anal Toxicol 26 87. 

A software filter which allows the removal of interference ions from drug metabolites in accurate mass liquid chromatography—mass spectrometry... 

Zhang, H. Zhang, D. Ray, K. A software filter to remove interference ions from drug metabolites in accurate mass liquid chromatography/ mass spectrometric analyses. J. Mass Spectrom. 2003, 38, 1110-1112. 

Black, R. Henion, J. High-throughput selected reaction monitoring liquid chromatography-mass spectrometry determination of methylphenidate and its major metabolite, ritalinic acid, in rat plasma employing monolithic columns. J Chromatogr B Anal Technol Biomed Life Sci 2003, 783, 73-83. 

F. Baumann and R. Preiss, Application of liquid chromatography-mass spectrometry in the determination of oxazaphosphorines and their metabolites. Analytica Chimica Acta, 2003,492(1-2), 147-156. 

The system relies upon preliminary fractionation of the microbial crude extract by dualmode countercurrent chromatography coupled with photodiode array detection (PDA). The ultraviolet-visible (UV-Vis) spectra and liquid chromatography-mass spectrometry (LC-MS) of biologically active peaks are used for identification. Confirmation of compound identity is accomplished by nuclear magnetic resonance (NMR). Use of an integrated system countercurrent chromatography (CCC) separation, PDA detection, and LC-MS rapidly provided profiles and structural information extremely useful for metabolite identification (dereplication, Figure 14.1). 

E Horne, A Cadogan, M Okeeffe, LAP Hoogenboom. Analysis of protein-bound metabolites of furazolidone and furaltadone in pig-liver by high-performance liquid chromatography and liquid chromatography-mass spectrometry. Analyst 121 1463-1468, 1996. 

Bakhtiar, R., and Majumdar, T. K. (2007). Tracking problems and possible solutions in the quantitative determination of small molecule chugs and metabolites in biological fluids using liquid chromatography-mass spectrometry. J. Pharmacol. Toxicol. Methods 55 227-243. 

Gu, M., Wang, Y., Zhao, X. G., and Gu, Z. M. (2006). Accurate mass filtering of ion chromatograms for metabolite identification using a unit mass resolution liquid chromatography/ mass spectrometry system. Rapid Commun. Mass Spectrom. 20 764-770. 

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