Chromatography2014, 1(3), 141-158; doi:10.3390/chromatography1030141 (registering DOI) - published 19 September 2014 Show/Hide Abstract
Abstract: In this work, the main organic acids (citric, malic and ascorbic acids) and sugars (glucose, fructose and sucrose) present in commercial fruit beverages (fruit carbonated soft-drinks, fruit nectars and fruit juices) were determined. A novel size exclusion high performance liquid chromatography isocratic green method, with ultraviolet and refractive index detectors coupled in series, was developed. This methodology enabled the simultaneous quantification of sugars and organic acids without any sample pre-treatment, even when peak interferences occurred. The method was in-house validated, showing a good linearity (R > 0.999), adequate detection and quantification limits (20 and 280 mg L−1, respectively), satisfactory instrumental and method precisions (relative standard deviations lower than 6%) and acceptable method accuracy (relative error lower than 5%). Sugars and organic acids profiles were used to calculate dose-over-threshold values, aiming to evaluate their individual sensory impact on beverage global taste perception. The results demonstrated that sucrose, fructose, ascorbic acid, citric acid and malic acid have the greater individual sensory impact in the overall taste of a specific beverage. Furthermore, although organic acids were present in lower concentrations than sugars, their taste influence was significant and, in some cases, higher than the sugars’ contribution towards the global sensory perception.
Abstract: Odour profiling of decomposed remains is important for understanding the mechanisms that cadaver dogs and forensically-relevant insects use to locate decomposed remains. The decomposition odour profile is complex and has been documented in outdoor terrestrial environments. The purpose of this study was to perform longitudinal analysis of the volatile organic compound (VOC) profile in soils associated with decomposed remains across all stages of decomposition. Two VOC collection techniques (sorbent tubes and solid phase microextraction) were used to collect a wider analyte range and to investigate differences in collection techniques. Pig carcasses were placed in an outdoor research facility in Australia to model the decomposition process and VOCs were collected intermittently over two months. VOCs of interest were identified over the duration of the trial, showing distinct trends in compound evolution and disappearance. The collection techniques were complementary, representing different subsets of VOCs from the overall profile. Sorbent tubes collected more decomposition-specific VOCs and these compounds were more effective at characterising the matrix over an extended period. Using both collection techniques improves the likelihood of identifying the complete VOC profile of decomposition odour. Such information is important for the search and recovery of victim remains in various stages of decomposition.
Abstract: Exhaled breath condensate (EBC) has been established as a potential source of respiratory biomarkers. Compared to the numerous small molecules identified, the protein content of EBC has remained relatively unstudied due to the methodological and technical difficulties surrounding EBC analysis. In this review, we discuss the proteins identified in EBC, by mass spectrometry, focusing on the significance of those proteins identified. We will also review the limitations surrounding mass spectral EBC protein analysis emphasizing recommendations to enhance EBC protein identifications by mass spectrometry. Finally, we will provide insight into the future directions of the EBC proteomics field.
Abstract: A new simple and quick method has been established for separation of Cu from solutions using an extraction chromatographic resin utilizing Aliquat® 336 (commercially available as TEVA™ resin) and Cu(I). This method involves the use of a one milliliter column containing 0.33 mL TEVA™ resin on 0.67 mL Amberchrom® CG-71C acrylic resin. Copper was adsorbed on the column by forming Cu(I) with 0.15% ascorbic acid in 0.05 mol·L−1 HBr, while other major elements except Zn showed no adsorption. After removal of the major elements (Na, Mg, Al, P, K, Ca, Cr, Mn, Fe, Co and Ni), Cu was recovered using 2 mol·L−1 HNO3. The recovery yield and total blank were 102% ± 2% and 0.25 ng, respectively. To evaluate the separation method, Cu isotope ratios were determined by a standard-sample-standard bracketing method using multicollector inductively coupled plasma-mass spectrometry (ICP-MS), with a repeatability of 0.04‰ and 0.25‰ (SD), for the standard solution and the solutions from low S (<0.1% S) silicate standards, respectively.
Abstract: Olaparib (AZD2281) is an orally active PARP-1 inhibitor, primarily effective against cancers with BRCA1/2 mutations. It is currently in Phase III development and has previously been investigated in numerous clinical trials, both as a single agent and in combination with chemotherapy. Despite this widespread testing, there is only one published method that provides assay details and stability studies for olaparib alone. A more sensitive uHPLC-MS/MS method for the quantification of olaparib in human plasma was developed, increasing the range of quantification at both ends (0.5–50,000 ng/mL) compared to previously published methods (10–5,000 ng/mL). The wider range encompasses CMAX levels produced by typical olaparib doses and permits better pharmacokinetic modeling of olaparib elimination. This assay also utilizes a shorter analytical runtime, allowing for more rapid quantification and reduced use of reagents. A liquid-liquid extraction was followed by chromatographic separation on a Waters UPLC® BEH C18 column (2.1 × 50 mm, 1.7 µm) and mass spectrometric detection. The mass transitions m/z 435.4→281.1 and m/z 443.2→281.1 were used for olaparib and the internal standard [2H8]-olaparib, respectively. The assay proved to be accurate (<9% deviation) and precise (CV < 11%). Stability studies showed that olaparib is stable at room temperature for 24 h. in whole blood, at 4 °C for 24 h post-extraction, at −80 °C in plasma for at least 19 months, and through three freeze-thaw cycles. This method proved to be robust for measuring olaparib levels in clinical samples from a Phase I trial.
Abstract: This paper describes a reserved-phase high-performance liquid chromatographic (HPLC) method for detecting malachite green (MG) and leuco-malachite green (LMG) using an isocratic toxic organic solvent/reagent-free mobile phase. Chromatographic separations were performed an Inertsil® WP300 C4 with 0.02 mol/L octane sulfonic acid–ethanol mobile phase and a photodiode-array detector. The total run time was <5 min. The system suitability was well within the international acceptance criteria. A harmless method for simultaneously detecting MG and LMG was developed and may be further applied to the quantification in foods.