Evaluation of the influence of protein precipitation prior to on-line SPE–LC–API/MS procedures using multivariate data analysis☆

Marchi, Ivano; Rudaz, Serge; Selman, Maurice H. J.; Veuthey, Jean‐Luc

doi:10.1016/j.jchromb.2006.08.045

Cited by 51 publications

(31 citation statements)

References 51 publications

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“…First, common solvents such as water, ACN or methanol (MeOH) are not affected by discharge lamp as their IPs are higher than 10 eV [29,36,37], thus resulting in a low background noise [37]. Second, APPI sources appear to be less sensitive to ion suppression (compared to APCI and above all to ESI) [28,31,[38][39][40][41]. Finally, APPI achieves significantly better sensitivity than APCI over a wider range of flow rates, particularly at the very low flow rates generated by CE separations.…”

Section: Introductionmentioning

confidence: 99%

Coupling CE with atmospheric pressure photoionization MS for pharmaceutical basic compounds: Optimization of operating parameters

Schappler¹,

Guillarme²,

Prat³

et al. 2007

Electrophoresis

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The use of CE coupled with MS (CE-MS) has evolved as a useful tool to analyze charged species in small sample volumes. Because of its sensitivity, versatility and ease of implementation, the ESI interface is currently the method of choice to hyphenate CE to MS. An alternative can be the atmospheric pressure photoionization (APPI) source, however, numerous parameters must be optimized for its coupling to CE. After evaluation of the sheath liquid composition and the CE capillary outlet position, an experimental design methodology was assessed for optimizing other ionization source parameters, such as sheath liquid flow rate, drying gas flow rate and temperature, nebulizing gas pressure, vaporizer temperature, and capillary voltage. For this purpose, a fractional factorial design (FFD) was selected as a screening procedure to identify factors which significantly influence sensitivity and efficiency. A face-centered central composite design (CCD) was then used to predict and optimize sensitivity, taking into account the most relevant variables. Sensitivity was finally evaluated with the optimized conditions and height-to-noise ratios (H/N) around 10 were achieved for an injection of 200 ng/mL of each analyte.

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Section: Introductionmentioning

confidence: 99%

Coupling CE with atmospheric pressure photoionization MS for pharmaceutical basic compounds: Optimization of operating parameters

Schappler¹,

Guillarme²,

Prat³

et al. 2007

Electrophoresis

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“…This method involved protein precipitation followed by solid-phase extraction. It has been reported that a protein precipitation procedure prior to solid-phase extraction was the least affected by matrix effects [22,23]. The LC-MS method described here provides sensitive, accurate, precise, reproducible and relatively fast simultaneous determinations of EAPB0503 and EAPB0603 in rat and human plasma.…”

Section: Discussionmentioning

confidence: 94%

Quantitation of imidazo[1,2‐a]quinoxaline derivatives in human and rat plasma using LC/ESI‐MS

Khier

Moarbess²,

Deleuze‐Masquéfa³

et al. 2009

J of Separation Science

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Original PaperQuantitation of imidazo[1,2-a]quinoxaline derivatives in human and rat plasma using LC/ESI-MS Since several years, our group developed quinoxalinic compounds. Among the synthesized compounds, in the imidazo[1,2-a]quinoxaline series, EAPB0203 has shown interesting activities both on melanoma and lymphoma. The structure of EAPB0203 has been modulated and a new compound, EAPB0503, exhibits an in vitro cytotoxic activity on melanoma cancer cell line 7 -9 times higher than EAPB0203. We validated an LC/ESI-MS method to simultaneously quantify EAPB0503 and its metabolite EAPB0603 in human and rat plasma. Chromatography was performed on a C8 Zorbax eclipse XDB column with a mobile phase consisting of acetronitrile and formate buffer gradient elution. LC-MS data were acquired in SIM mode at m/z 305, 291, and 303 for EAPB0503, EAPB0603, and the internal standard, respectively. The drug/ internal standard peak area ratios were linked via quadratic relationships to concentrations (low range: 5 -300 lg/L, high range: 100 -1000 lg/L). The method is precise (precision, f14%) and accurate (recovery, 92 -113%). Mean extraction efficiencies, A72% for each analyte, were obtained. The lower LOQs were 5 lg/L. This highly specific and sensitive method was successfully used to investigate plasma concentrations of EAPB0503 and EAPB0603 in a pharmacokinetic study carried out in rat and would also be useful in clinical trials at a later stage.Keywords: Human and rat matrices / Imidazo[1,2-a]quinoxaline / LC/ESI-MS / Lymphoma / Melanoma /

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“…Varenicline tartrate (VT) (7,8,9,10-tetrahydro-6,10-methano-6H-pyrazino [2,3-h] [3] benzazepine) was recently introduced as a novel efficacious smoking cessation aid that acts as an α4β2 nicotinic acetylcholine receptor (nAChRs) partial agonist, centrally acting as a highly selective partial agonist for the nicotinic acetylcholine receptor [1][2] . Varenicline has mixed agonistic-antagonistic properties, thus it has the therapeutic benefit of relieving the symptoms of nicotine withdrawal and cigarette craving during abstinence while blocking the reinforcing effect of nicotine in those who lapse 3 .…”

Section: Introductionmentioning

confidence: 99%

“…The accurate quantification of agents in biological matrices such as blood, serum, urine and tissue samples is the cornerstone of therapeutic drug monitoring. Therefore, detailed specific, reproducible and accurate method for the quantification of VT is necessary [7][8] . Additionally, examining the matrix effects represents an important issue in liquid chromatography tandem mass spectrometric (LC-MS/MS), particularly when dealing with biological matrices such as biological fluids.…”

Section: Introductionmentioning

confidence: 99%

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2016

IJPSR

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ABSTRACT:The objective of this research was to develop and validate a simple, sensitive and specific Liquid Chromatography -Tandem Mass Spectrometry (LC-MS/MS) quantification of Varenicline in human plasma using Varenicline -D4 as Internal Standard (IS). The analyte was separated on a Zorbax SB-C18, 4.6 x 75 mm, 3.5 μm, 80 Å column with an isocratic mobile phase of 5mM ammonium formate: acetonitrile (10:90 v/v) at a flow rate of 0.8 mL/min. The protonated ions were formed by a turbo ionspray in a positive mode was used to detect analyte and internal standard (IS). The analytes were monitored by electrospray ionization in positive ion multiple reaction monitoring (MRM) mode was used to detect the Varenicline at m/z 212.1/169.0. This method is validated over a linear concentration range of 50.0-10000.0 pg/mL with a correlation coefficient (r) of ≥ 0.9997. Both drug and internal standards were stable in plasma samples. This method demonstrated intra and inter-day precision within 1.2-4.5 and 3.5-7.4 and accuracy within 91.70-105.5% and 103.9-110.6%.

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Evaluation of the influence of protein precipitation prior to on-line SPE–LC–API/MS procedures using multivariate data analysis☆

Cited by 51 publications

References 51 publications

Coupling CE with atmospheric pressure photoionization MS for pharmaceutical basic compounds: Optimization of operating parameters

Coupling CE with atmospheric pressure photoionization MS for pharmaceutical basic compounds: Optimization of operating parameters

Quantitation of imidazo[1,2‐a]quinoxaline derivatives in human and rat plasma using LC/ESI‐MS

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