Development of a sample preparation procedure for Sr isotope analysis of Portland cements

The 87Sr/86Sr isotope ratio can, in principle, be used for provenancing of cement. However, while commercial cements consist of multiple components, no detailed investigation into their individual 87Sr/86Sr isotope ratios or their influence on the integral 87Sr/86Sr isotope ratio of the resulting cement was conducted previously. Therefore, the present study aimed at determining and comparing the conventional 87Sr/86Sr isotope ratios of a diverse set of Portland cements and their corresponding Portland clinkers, the major component of these cements. Two approaches to remove the additives from the cements, i.e. to measure the conventional 87Sr/86Sr isotopic fingerprint of the clinker only, were tested, namely, treatment with a potassium hydroxide/sucrose solution and sieving on a 11-µm sieve. Dissolution in concentrated hydrochloric acid/nitric acid and in diluted nitric acid was employed to determine the 87Sr/86Sr isotope ratios of the cements and the individual clinkers. The aim was to find the most appropriate sample preparation procedure for cement provenancing, and the selection was realised by comparing the 87Sr/86Sr isotope ratios of differently treated cements with those of the corresponding clinkers. None of the methods to separate the clinkers from the cements proved to be satisfactory. However, it was found that the 87Sr/86Sr isotope ratios of clinker and cement generally corresponded, meaning that the latter can be used as a proxy for the clinker 87Sr/86Sr isotope ratio. Finally, the concentrated hydrochloric acid/nitric acid dissolution method was found to be the most suitable sample preparation method for the cements; it is thus recommended for 87Sr/86Sr isotope analyses for cement provenancing. Graphical abstract

Development of a high-performance liquid chromatography method for simultaneously analyzing Guanosine 5’-monophosphate (GMP) and Inosine 5’-monophosphate (IMP) in food

This study aimed to develop a HPLC method to simultaneously analyze guanosine 5’-monophosphat (GMP) and inosine 5’-monophosphat (IMP) in food products. Sample preparation procedure was simple, fast. A C18 column (250 mm × 4.6 mm, 5 µm) was used as stationary phase, and a mixture of 10 mM potassium dihydrogen phosphate and 5 mM sodium heptanesulfonate was applied as mobile phase, and PDA detector at 250 nm. The method validation followed AOAC criteria. Selectivity, linearity (R2 > 0.999), recovery (IMP: 90.5 % - 102.8 %, GMP: 91.5 % - 103.9 %), repeatability (RSDR of IMP: 3.07 % and GMP: 2.83 %) were acceptable to determination GMP and IMP in food matrix under AOAC guidelines. LOD of GMP and IMP were of 2.32 and 2.77 mg/kg, respectively. This method was used to determination GMP, IMP in food products collected in Hanoi markets.

Development of Comprehensive Analysis of Pyrolysis Products for Lignocellulose Raw Materials and Sludge Sediments by Chromatographic Methods

This paper presents a study of the pyrolysis products organic raw materials (bio-oil and sludge sediments of treatment facilities) by chromatographic methods. A feature of the work is to optimize the sample preparation procedure by fractionating the pyrolysis products. Using the method of gel permeation chromatography, molecular weight distribution of pyrolysis products was assessed. Determination of the water content in these objects (by Karl Fischer titration) was used to assess the possibility of their direct analysis by gas chromatography. A sample of sludge pyrolysis and several fractions obtained from a bio-oil sample were analyzed. By the method of two-dimensional gas chromatography, where a selfdeveloped column based on an ionic liquid was used as the first measurement column, the pyrolysate of sludge sediments and the ether fraction of bio-oil were analyzed. The obtained chromatograms and quantitative results are presented

Analytical Methodology for a Metabolome Atlas of Goat’s Plasma, Milk and Feces Using 1H-NMR and UHPLC-HRMS

Metabolomics has been increasingly used in animal and food sciences. Animal health is one of the most important factor that can also alter animal integrity and welfare. Some studies have already investigated the link between health and metabolic profile of dairy animals. These studies in metabolomics often consider a single type of sample using a single analytical platform (nuclear magnetic resonance or mass spectrometry). Only few studies with multi-platform approaches are also used with a single or a multi type of sample, but they mainly consider dairy cows’ metabolome although dairy goats present similar diseases, that it could be interesting to detect early to preserve animal health and milk production. This study aims to create a metabolic atlas of goat plasma, milk and feces, based on healthy animals. Our study describes a standard operating procedure for three goat matrices: blood plasma, milk, and feces using multiple platforms (NMR (1H), UHPLC (RP)-MS and UHPLC (HILIC)-MS) that follows a unique sample preparation procedure for each sample type to be analyzed on multi-platforms basis. Our method was evaluated for its robustness and allowed a better characterization of goat metabolic profile in healthy conditions.

Hydrophilic Interaction Liquid Chromatography Coupled with Fluorescence Detection (HILIC-FL) for the Quantitation of Octreotide in Injection Forms

Octreotide is a synthetic cyclic octapeptide analogue of somatostatin-14. It is mainly administered for the treatment of acromegaly, severe diarrhea, and neuroendocrine neoplasias. In this work, a hydrophilic interaction liquid chromatography (HILIC) method with fluorescence (FL) detection was developed and validated for the quantitation of octreotide in solutions for injection. Chromatographic separation was performed on an XBridge®-HILIC analytical column under isocratic elution with a short chromatographic run time of less than 10 min. The mobile phase consisted of ammonium bicarbonate 8.6 mM (pH 8.1)/acetonitrile 35/65 (v/v). The high sensitivity and selectivity of the fluorescence detection, with the excitation wavelength (λexcitation) set at 280 nm and the emission wavelength set at (λemission) 330 nm, enabled a simple sample preparation procedure that included only dilution steps. The calibration curve showed good linearity with a correlation coefficient greater than 0.998. The method was successfully applied to the analysis of commercially available octreotide injection forms.

A Method to Monitor the NAD+ Metabolome—From Mechanistic to Clinical Applications

Nicotinamide adenine dinucleotide (NAD+) and its reduced form (NADH) are coenzymes employed in hundreds of metabolic reactions. NAD+ also serves as a substrate for enzymes such as sirtuins, poly(ADP-ribose) polymerases (PARPs) and ADP-ribosyl cyclases. Given the pivotal role of NAD(H) in health and disease, studying NAD+ metabolism has become essential to monitor genetic- and/or drug-induced perturbations related to metabolic status and diseases (such as ageing, cancer or obesity), and its possible therapies. Here, we present a strategy based on liquid chromatography-tandem mass spectrometry (LC-MS/MS), for the analysis of the NAD+ metabolome in biological samples. In this method, hydrophilic interaction chromatography (HILIC) was used to separate a total of 18 metabolites belonging to pathways leading to NAD+ biosynthesis, including precursors, intermediates and catabolites. As redox cofactors are known for their instability, a sample preparation procedure was developed to handle a variety of biological matrices: cell models, rodent tissues and biofluids, as well as human biofluids (urine, plasma, serum, whole blood). For clinical applications, quantitative LC-MS/MS for a subset of metabolites was demonstrated for the analysis of the human whole blood of nine volunteers. Using this developed workflow, our methodology allows studying NAD+ biology from mechanistic to clinical applications.

Application of robust parameter design in the development of a quantitative chemical analysis procedures in metallurgy

The paper presents the results of experimental research for the quantitative chemical analysis procedures using the robust parameter design methodology. There is an example of the parameter design in development of the measurement procedure for the mass fraction of chlorine in dusty waste in the ferronickel production. Results of experiment analysis has provided an information about the optimal conditions for sample preparation procedure.

Optimization of Sample Preparation for Metabolomics Exploration of Urine, Feces, Blood and Saliva in Humans Using Combined NMR and UHPLC-HRMS Platforms

Currently, most clinical studies in metabolomics only consider a single type of sample such as urine, plasma, or feces and use a single analytical platform, either NMR or MS. Although some studies have already investigated metabolomics data from multiple fluids, the information is limited to a unique analytical platform. On the other hand, clinical studies investigating the human metabolome that combine multi-analytical platforms have focused on a single biofluid. Combining data from multiple sample types for one patient using a multimodal analytical approach (NMR and MS) should extend the metabolome coverage. Pre-analytical and analytical phases are time consuming. These steps need to be improved in order to move into clinical studies that deal with a large number of patient samples. Our study describes a standard operating procedure for biological specimens (urine, blood, saliva, and feces) using multiple platforms (1H-NMR, RP-UHPLC-MS, and HILIC-UHPLC-MS). Each sample type follows a unique sample preparation procedure for analysis on a multi-platform basis. Our method was evaluated for its robustness and was able to generate a representative metabolic map.