A bioanalytical screening method for Enterococcus faecalis RNPP-type quorum sensing peptides in murine feces

Background: Bacteria coordinate their behavior as a group via communication with their peers, known as ‘ quorum sensing’. Enterococcus faecalis employs quorum sensing via RNPP-peptides which were not yet reported to be present in mammalian biofluids. Results: Solid phase extraction of murine feces was performed, followed by ultra high performance liquid chromatography (UHPLC–MS/MS) in multiple reaction monitoring (MRM) mode (in total <90 min/sample) for the nine known RNPP peptides. Limits of detection ranged between 0.045 and 52 nM. Adequate identification criteria allowed detection of RNPP quorum sensing peptides in 2/20 wild-type murine feces samples (i.e., cAM373 and cOB1). Conclusion: A fit-for-purpose UHPLC–MS/MS method detected these RNPP peptides in wild-type murine feces samples.

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Screening of Danish traffic cases for synthetic cannabinoids in whole blood by LC-MS/MS

Scandinavian Journal of Forensic Science ◽

10.2478/sjfs-2013-0008 ◽

2013 ◽

Vol 19 (2) ◽

pp. 45-51 ◽

Cited By ~ 5

Author(s):

Niels Bjerre Holm ◽

Rebeca Sequera Pineda ◽

David Wederkinck Andersen ◽

Brian Schou Rasmussen ◽

Petur Weihe Dalsgaard ◽

...

Keyword(s):

Whole Blood ◽

Limit Of Detection ◽

Solid Phase ◽

Multiple Reaction Monitoring ◽

Synthetic Cannabinoids ◽

Screening Method ◽

Driving Under The Influence ◽

Reaction Monitoring ◽

Multiple Reaction Monitoring Mode ◽

Target Screening

ABSTRACT A target screening method for the detection of 13 synthetic cannabinoids in whole blood was developed and validated. Samples underwent automated solid-phase extraction, and sample extracts were analyzed by liquid chromatography-positive electrospray ionization-tandem mass spectrometry using two transitions in multiple reaction monitoring mode. The limit of detection was between 0.1-2.5 ng/mL for the compounds except HU-210, and extraction recovery ranged from 59 to 78%. The method was used to screen 393 Danish traffic cases from 2012, where the driver was suspected of driving under the influence of drugs. No synthetic cannabinoids were identified in these samples. Additionally, the method was applied to a clinical intoxication case, and the synthetic cannabinoid AM- 2201 was identified in serum. We conclude that the prevalence of driving under the influence of synthetic cannabinoids in Denmark is likely to be low, and that synthetic cannabinoids are most likely to be encountered in the clinical setting.

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LC-MS/MS Quantification of Tramadol and Gabapentin Utilizing Solid Phase Extraction

International Journal of Analytical Chemistry ◽

10.1155/2018/1605950 ◽

2018 ◽

Vol 2018 ◽

pp. 1-9 ◽

Cited By ~ 3

Author(s):

Pappula Nagaraju ◽

Balaji Kodali ◽

Peda Varma Datla ◽

Surya Prakasarao Kovvasu

Keyword(s):

Solid Phase Extraction ◽

High Performance ◽

Solid Phase ◽

Multiple Reaction Monitoring ◽

Internal Standard ◽

Phase Extraction ◽

Linear Calibration ◽

Internal Standards ◽

Peak Resolution ◽

Highly Sensitive

An accurate, highly sensitive, and precise method for quantitative analysis of tramadol (TMD) and gabapentin (GBP) by high performance liquid chromatography and tandem mass spectrometry in human plasma was proposed and validated successfully using venlafaxine and pregabalin as internal standards (ISTDs), respectively. An aliquot of 200 μL of plasma was mixed with internal standard dilution and extraction was performed by using solid phase extraction (SPE) technique. Peak resolution was achieved on Phenomenex PFP column (50×4.6 mm, 2.6 μm). The total analytical run time was 3.8 min. Both analytes were monitored using multiple reaction monitoring (MRM) scan and the mass spectrometer was operated in positive polarity mode. The method was validated for specificity, sensitivity, precision, accuracy, and other analytical parameters. The results found were satisfactory over the linear calibration range of 1-500 ng/mL and 10-6000 ng/mL for TMD and GBP, respectively. The developed method can be ready to use by scientific community for quantification of analytes in plasma samples from various clinical studies of different dose strengths.

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