Agilent Technologies (Australia)

Background: Triamterene is a potassium-conserving diuretic mainly used in the treatment of edematous diseases. Although there are some methods to measure the content of triamterene, the existing methods have the characteristics of sample destructiveness and low flux, making it difficult to meet the needs of online monitoring. In recent years, transmission Raman spectroscopy (TRS), as a new technology for the determination of drug content, has emerged as being nondestructive and rapid and provides a new method for the determination of triamterene content. Objective: In this study, we used transmission Raman spectroscopy combined with partial least squares (PLS) approaches to establish a six concentration levels model for measuring the content of triamterene. The model was applied to determine whether tablets are commercially available. Methods: Firstly, TRS was used to collect the spectra of the principal components and mixed excipients of triamterene, and the feasibility test was carried out. Secondly, six concentration levels were determined by the design of experimental (DOE), and hand-made tablets were prepared to obtain corresponding spectra. The content prediction model was established by the PLS method, and the content of triamterene was determined by high-performance liquid chromatography (HPLC) to correct the model. Finally, the model was applied to the determination of triamterene in commercially available tablets. Results: The results showed that the established model was successfully applied to the determination of triamterene. The values of RMSEC (0.0089783) and RMSECV (0.0097241) of the final model were very low and close to each other. The relative error of 12 hand-made tablets predicted by this model was less than 5% compared with the results determined by HPLC. In addition, in the process of applying the model to the determination of the content of commercially available tablets, the accuracy of the model can be significantly improved by adding the spectrum of commercially available tablets. The corrected model was used to determine the content of triamterene in two commercially available tablets. The results showed that the relative error was less than 5%. Conclusion: We described a new strategy to analyze the content of active pharmaceutical ingredients (API) in triamterene tablets by TRS with PLS. The established model has the advantage of non-destructive and rapid quantitation, which can provide a new method for real-time monitoring of production lines and promote the development of process analytical technology (PAT).

ABSTRACT The detection and quantification of compounds present in smokeless powders plays an important role in various fields such as environmental and forensic science. Often, time and labour consuming sample preparation techniques such as solid phase extraction (SPE) are required to facilitate either pre-concentration or sample clean-up with complex matrices. This paper describes the first application of the completely automated online SPE system RapidFire® connected to a triple quadrupole mass spectrometer for smokeless powder/gunshot residue analysis. The optimized method involved sample loading during 2000 ms using UP water (0.1% formic acid) at a flowrate of 1.25 mL/min on a Type C C18 cartridge followed by elution of the target compounds for 3000 ms using IPA (0.1% formic acid) at 0.75 mL/min. Target compounds were detected in soil (DPA, 2-NDPA, EC, NG, 2,4-DNT) and cotton swabs (NG) in only 8 seconds per sample with detection limits of 0.223 ppm (DPA), 0.104 ppm (2-NDPA), 0.0949 ppm (EC), 0.187 ppm (NG) and 0.128 ppm (2,4-DNT). The presented method showed promising results for the analysis of five target analytes in soil samples. Further optimisations can extend the analysis to other sample matrices and include more analytes potentially present in smokeless powders and GSR.

In this work, gas chromatography tandem with electron ionization and full-scan high-resolution mass spectrometry with a time-of-flight mass analyzer was evaluated for analyzing pesticide residues in teas. The relevant aspects for mass spectrometry analysis, including the resolution and mass accuracy, acquisition rate, temperature of ion source, were investigated. Under acquisition condition in 2-GHz extended dynamic range mode, accurate mass spectral library including 184 gas chromatography detectable pesticides was established and retrieval parameters were optimized. The mass spectra were consistent over a wide concentration range (three orders) with good match values to those of NIST (EI-quadrupole). The methodology was verified by the validation of 184 pesticides in four tea matrices. A wide linear range (1-1000 μg/kg) was obtained for most compounds in four matrices. Limit of detection, limit of quantification, and limit of identification values acquired in this study could satisfy the requirements for maximum residue levels prescribed by the European Community. Recovery studies were performed at three concentrations (10, 50, and 100 μg/kg). Most of the analytes were recovered at an acceptable range of 70-120% with relative standard deviations ≤ 20% in four matrices. The potential extension of qualitative screening scope makes gas chromatography tandem with electron ionization and mass spectrometry with a time-of-flight mass analyzer a more powerful tool compared with gas chromatography with tandem mass spectrometry.

Abstract Macrophage is a critical microenvironmental component which can control tumor progression, and dynamic changes in cellular metabolism accompany the polarization. As well as other immune cells, the activation of macrophages can be modulated by cancer cells. Cancer-derived exosome is a newly emerging microenvironmental factor enables cancer cells to communicate with macrophages. In this study, examined were the activation-associated bioenergetic changes and the effect of cancer cell-derived exosome on the changes by a) monitoring the early metabolic kinetics and b) profiling bioenergetic phenotype resulted. In vitro activation of RAW264.7 macrophage cell line by injecting lipopolysaccharide (LPS) and interferon γ (IFNγ) in a Seahorse XF analyzer induced an immediate early increase in glycolytic rate. It also showed a delayed down-regulation of mitochondrial respiration, which resulted in a secondary elevation of glycolytic rate. This secondary glycolytic response was only obtained by LPS-IFNγ co-stimulation and mediated by induced nitric oxide synthase (iNOS) signaling. In contrast to the dynamic changes in metabolic phenotype, the total ATP production rate appeared to be stably maintained according to the XF data normalized by cell number. However, macrophage activation significantly increased glycolysis-dependent portion of ATP production. ATPs were generated almost solely by glycolysis after the delayed mitochondrial down-regulation by iNOS. Co-injection of cancer cell-derived exosomes with LPS slightly but significantly accelerated the immediate early glycolytic response as well as the delayed mitochondrial down-regulation. Furthermore, exosomes induced the immediate early glycolytic response even in the absence of LPS. These results imply that presence of cancer cell-derived exosomes may promote macrophage activation and accelerate pro-inflammatory immune response in a tumor microenvironment. Citation Format: Yoonseok Kam, Brian P. Dranka. Effect of cancer cell-derived exosome on energy metabolism associated with macrophage activation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 62.

An ultra performance liquid chromatography-quadrupole/electrostatic field orbitrap high resolution mass spectrometry (UPLC-Q Orbitrap HRMS) method was developed for the rapid screening of 25 drug residues in aquatic products by the application of a novel enhanced matrix removal of lipids (EMR-Lipid). The samples were extracted with acetonitrile, cleaned-up with EMR-Lipid, and salted out with 3.0 g sodium chloride and 3.0 g sodium sulfate. The separation of the 25 drug residues was performed on an ACQUITY UPLC BEH C18 column (100 mm×2.1 mm, 1.7 μm) with gradient elution. Acetonitrile containing 0.1% (v/v) formic acid and 0.1% (v/v) formic acid aqueous solution were used as mobile phases. The compounds were detected by Full scan/date dependent MS/MS (Full MS/dd-MS2) via heated electrospray ionization (HESI) source. The calibration curves were linear with correlation coefficients (r) greater than 0.997. The limits of detection (LODs) ranged from 0.1 μg/kg to 1.0 μg/kg. The average spiked recoveries of the 25 target compounds were between 70.1% and 108.9% with relative standard derivations (RSDs) from 2.1% to 13.8%. Compared with the previous methods, this method has characteristics of simpler sample preparation and higher sensitivity.