A Rapid and Simple UHPLC-MS/MS Method for Quantification of Plasma Globotriaosylsphingosine (lyso-Gb3)

Fabry disease (FD) is a rare X-linked lysosomal storage disorder caused by α-galactosidase A gene (GLA) mutations, resulting in loss of activity of the lysosomal hydrolase, α-galactosidase A (α-Gal A). As a result, the main glycosphingolipid substrates, globotriaosylceramide (Gb3) and globotriaosylsphingosine (lyso-Gb3), accumulate in plasma, urine, and tissues. Here, we propose a simple, fast, and sensitive method for plasma quantification of lyso-Gb3, the most promising secondary screening target for FD. Assisted protein precipitation with methanol using Phree cartridges was performed as sample pre-treatment and plasma concentrations were measured using UHPLC-MS/MS operating in MRM positive electrospray ionization. Method validation provided excellent results for the whole calibration range (0.25–100 ng/mL). Intra-assay and inter-assay accuracy and precision (CV%) were calculated as <10%. The method was successfully applied to 55 plasma samples obtained from 34 patients with FD, 5 individuals carrying non-relevant polymorphisms of the GLA gene, and 16 healthy controls. Plasma lyso-Gb3 concentrations were larger in both male and female FD groups compared to healthy subjects (p < 0.001). Normal levels of plasma lyso-Gb3 were observed for patients carrying non-relevant mutations of the GLA gene compared to the control group (p = 0.141). Dropping the lower limit of quantification (LLOQ) to 0.25 ng/mL allowed us to set the optimal plasma lyso-Gb3 cut-off value between FD patients and healthy controls at 0.6 ng/mL, with a sensitivity of 97.1%, specificity of 100%, and accuracy of 0.998 expressed by the area under the ROC curve (C.I. 0.992 to 1.000, p-value < 0.001). Based on the results obtained, this method can be a reliable tool for early phenotypic assignment, assessing diagnoses in patients with borderline GalA activity, and confirming non-relevant mutations of the GLA gene.

THE DETECTION OF BIMODE STATES FROM DEAF CAVITY THROUGH IONIZATION METHOD OF THE ATOMIC STATES

The equations of motion for the Raman and hyper-Raman conversion effect of atomic polarization are presented. At the same time, an experimental scheme previously used in the micromaser is proposed, which allows the determination of the number of atoms in the excited or in the ground state using the ionization method from the deaf cavity. Therefore, a method is proposed to link the number of atoms that have passed in the basic state of the induced-cooperative process of Stokes-type photon transformation in anti-Stokes (AS) photons in the case of Raman emission (RE) (following the micromaser model) or the transformation of photon pairs in the case of hyper-Raman emission (HRE)/

Using matrix-assisted ionization method for mass spectral identification of fullerene-dye conjugates

Traditional soft ionization methods are not always suitable for mass spectral analysis of complex compounds. Factors such as laser radiation and heating resulting in fragmentations of sample molecules in the case of matrix-assisted laser desorption/ionization and difficulties in preparing suitable sample solutions in the case of electrospray ionization make it impossible to use these methods in some cases. Matrix-assisted ionization was used to analyze products of chemical synthesis involving pyropheophorbide and fullerene. Mass spectra were acquired using a simple effective modification of the Exactive Orbitrap mass spectrometer electrospray interface. Reliable identification of pyropheophorbide-fullerene dyad ions and its derivatives was carried out. An experimental comparison of a matrix-assisted ionization and an electrospray ionization technique demonstrated the significant advantage in sensitivity to the ions under study (approximately 20 times higher) of the matrix-assisted ionization method in this particular study.

Validation of Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry Coupled with Electrospray Ionization Method for Quantitative Determination of Ornidazole in Solid Dispersion

Background and Objective: The present study describes the UPLC-MS/MS method validation for the analysis of ornidazole in solid dispersion. Methods: The proposed UPLC-MS/MS method utilizes BEH Shield RP18 column (2.1 mm 100 mm, 1.7 μm) with a gradient programmed mobile phase composed of water and acetonitrile at a flow rate of 0.4 mL/min which varies with time program. Ornidazole was detected by UPLC-MS/MS with three proton adducts at m/z 82.04, 128.05 as daughter ions and 220.03 as a parent ion in Multiple Reaction Monitoring (MRM) operated in positive mode. Results: Adducts at m/z 128.05 was found to be the most stable and showed higher intensity was selected for quantification of ornidaozle in solid dispersion. In the method, validation linearity was determined at concentration range of 10-100ng/mL and a correlation coefficient was found (r2) ≥0.9994. The limit of detection and limit of quantification were found to be 1.5 and 4 ng/mL, respectively. Inter and Intra-day precision was found within 0.33 and 0.11% and accuracy within 100.08% and 100.04%. Conclusion: A sensitive and selective UPLC-MS/MS method had been validated for the analysis of ornidazole in solid dispersion. The proposed method of analysis of ornidazole in solid dispersion can be used in quality control laboratories.