Single Quadrupole Research Articles

Composition of Hydrocarbons in Diamonds, Garnet, and Olivine from Diamondiferous Peridotites from the Udachnaya Pipe in Yakutia, Russia

Volatile components in diamonds, associated garnet (pyrope), and olivine from two extremely rare xenoliths of diamondiferous peridotites recovered from the Udachnaya kimberlite pipe in Yakutia, Russia, were analyzed by gas chromatography–mass spectrometry (GC–MS) using a Focus DSQ II Series Single Quadrupole GC–MS (Thermo Scientific, USA). These xenoliths are pyrope lherzolite and pyrope dunite based upon compositions of coexisting minerals. Unlike the pyrope lherzolite, which contained pyrope with moderate calcium (Ca)-component content (about 15 mol%), the dunite contained subcalcic chromium (Cr)-pyrope with low Ca-component content (less than 10 mol%). All investigated minerals contained dominating hydrocarbons and their derivatives represented by aliphatic (paraffins, olefins), cyclic (naphthenes, arenes), oxygenated (alcohols, ethers), and heterocyclic (dioxanes, furans) hydrocarbons; nitrogenated, chlorinated, and sulfonated compounds; carbon dioxide (CO2); and water (H2O). The relative concentration (rel%) of total hydrocarbon was 79.7 rel% for diamonds, 69.1 rel% for garnet, and 92.6 rel% for olivine, with a general amount of components ranging from 161 to 206. New data on volatiles in diamonds, associated garnet, and olivine suggest the presence of a wide spectrum of hydrocarbons along with nitrogen (N2), CO2, and H2O in some upper mantle areas.

Determination of volatile non intentionally added substances coming from a starch-based biopolymer intended for food contact by different gas chromatography-mass spectrometry approaches

The rapid growth of polymer technology in the field of food contact materials (FCMs) needs to be supported by continuous improvement in material testing, in order to ensure the safety of foodstuff. In this work, a range of different starch-based biopolymer samples, in the shape of pellets and retail samples (cups and dishes) were studied. The optimized extraction process was performed on three different pellet shapes: pellets with no modification (spherical), pellets shattered under high pressure (lentils), and pellets cryogenically ground (powder). The analysis of unknown volatile and semi-volatile compounds was carried out by gas chromatography-mass spectrometry, using both electron ionization with a single quadrupole mass analyzer (GC-EI-MS), and atmospheric pressure gas chromatography with a quadrupole/time of flight mass analyzer (APGC-Q/ToF). The identification process was implemented using the latest advances in the understanding of APGC ionization pathways. Chemical migration was also assessed on prototype samples using the food simulants: ethanol 10% v/v, acetic acid 3% w/V, ethanol 95% v/v, isooctane, and vegetable oil. Each migration test was performed three consecutive times, as recommended for materials intended for repeated use.

Novel Dechlorane Analogues and Possible Sources in Peregrine Falcon Eggs and Shark Livers from the Western North Atlantic Regions

During the investigation of dechlorane-related chemicals in North American wildlife, two unknown polychlorinated compounds (referred to as U1 and U2) were discovered. After extensive sample cleanup, structural information on U1 and U2 was characterized by gas chromatography (GC) coupled with single quadrupole mass spectrometer (MS) or GC-quadrupole time-of-flight (QToF) MS. Mass spectral evidence suggests that both U1 and U2 are structurally related to Dechlorane 603 (Dec603; C17H8Cl12), an analogue of the chlorinated flame retardant Dechlorane Plus. From the results we suspect U1 (C17H9Cl11) to be a monohydro analogue of Dec603 (i.e., one chlorine atom in Dec603 is replaced by a hydrogen atom). U1 may be formed via the degradation of Dec603's stereoisomers or present as an impurity in commercial Dec603 products. Mass spectral characterization of U2 (C17H7OCl11) suggests it is a carbonylic derivative of Dec603, likely formed via metabolic transformation of Dec603 or its photoisomer. Semiquantitative measurement revealed that U1 and U2 were present at estimated median concentrations of 49 ng/g lipid weight (lw) and 59 ng/g lw in peregrine falcon ( Falco peregrinus) eggs, from the mid-Atlantic region of the United States, and 4.6 and 3.0 ng/g lw in shortfin mako shark ( Isurus oxyrinchus) livers from the western North Atlantic Ocean, respectively. Our results demonstrate the occurrence of these two novel Dec603-related chemicals in both terrestrial and aquatic ecosystems.

Liquid Chromatography Method for the Simultaneous Quantification of Biotin and Vitamin B12 in Vitamin B Supplements.

Background: The determination of cyanocobalamin (vitamin B12) and biotin has always been challenging because of the lack of a chromophore for biotin and trace level input for vitamin B12 in supplements. Microbiological assay methods are currently used for quantitation. However, these methods are time consuming, may lack specificity, and have high imprecision. Objective: Our laboratory developed and validated an LC method for the simultaneous quantitation of vitamin B12 and biotin. Methods: This LC method uses a single quadruple mass analyzer to detect biotin and vitamin B12 at m/z 245.10 and m/z 678.29, respectively. Results: The mass analyzer allows for low limits of quantitation (biotin: 1 ng/mL; vitamin B12: 4 ng/mL). Precision results showed that injections are repeatable without the use of an internal standard (RSD < 5%). Single analyst (n = 5: RSD < 3%), within lab (n = 10: RSD < 8%), and multilab (n = 20: RSD < 13%) precision results were also much better than those reported by microbiological assay methods. Linearity was evaluated between 92.00 ng/mL and 9200 ng/mL (R² 09916) for biotin and between 4.846 ng/mL and 484.6 ng/mL (R² 0.9999) for vitamin B12. The method is accurate between 20 ng/mL and 60 ng/mL for vitamin B12 and between 400 ng/mL and 1200 ng/mL for biotin. Conclusions: The results show a simple, accurate, and precise method for the quantitation of vitamin B12 and biotin. Highlights: This work demonstrates that single quadrupole mass analyzers can be successfully used to quantify trace level analytes in quality control laboratories.

Simple GC–MS method for analysis of Levetiracetam and process-related toxic impurity

Levetiracetam (LEV) has been used for the treatment of epilepsy, especially partial seizures, owing to its pharmacokinetic profile, but the LEV impurity C (IMPC), pyridine-2-ol, is regarded as a main toxic substance. The existing methods for the analysis of LEV and its impurity are not fully effective. This study aimed to develop a simple gas chromatography-mass spectrometric (GC–MS) technique, for the first time, to analyze LEV and its toxic IMP-C without derivatization process, and to compare the technique with the previously reported UPLC method. Two different dosage forms of LEV, i.e. the tablet and syrup, plus IMP-C were determined by the same procedure. The analysis, without any derivatization processes, was performed using the gas chromatography coupled with Single Quadrupole Mass Spectrometer in the selected ion monitoring (SIM) mode that used electron ionization with 70 eV energy from 4 to 400 Amu. The helium carrier gas was run through a TG-5MS column with the flow rate of 1 mL/min via temperature programming. USP validation parameters were employed for the method validation regarding linearity and accuracy. The proposed method was successfully utilized to determine LEV in the tablet and syrup dosage forms. The statistical analysis showed no significant difference (p > 0.05) between this novel technique and the available UPLC method. Overall, the newly developed chromatographic method is characterized as simple and very sensitive for the simultaneous analysis of LEV and its impurity.

Determination of ellagic acid in rose matrix by spectrofluorimetry

Ellagic acid is a naturally occurring polyphenol with many verified and alleged bioactivities. This study presents a validated, sensitive and fast spectrofluorimetric method to determine ellagic acid in rose matrix, based on the fluorescence properties of ellagic acid–borax complex in methanolic extract. In the presence of rose matrix, a calibration curve was linear in a wide concentration range from 0.5 nmol/L to 1.0 μmol/L of EA, and the detection and quantification limits of ellagic acid were 34.7 nmol/L and 0.11 μmol/L, respectively. We used the validated method to determine the content of ellagic acid in lyophilized and dried rosehip products available in Poland. The rosehip contains a significant content of ellagic acid (from 32 to 44 μg/g of dried/freeze-dried material). All spectrofluorimetric results were in good agreement with those obtained by liquid chromatography–mass spectrometry with a single quadrupole analyzer used as a reference method.

Modeling the fragmentation patterns of triacylglycerides in mass spectrometry allows the quantification of the regioisomers with a minimal number of standards

Mass spectrometry allows the relative quantification of the regioisomers of triacylglycerides by the calibration of their fragmentation patterns. However, due to the plethora of regioisomers of triacylglycerides, calibration with every standard is not feasible. An analytical challenge in the field is the prediction of the fragmentation patterns of triacylglycerides to quantify their regioisomers. Thus, we aimed to model these fragmentation patterns to quantify the regioisomeric composition, even for those without commercially available standards. In a first step, we modeled the fragmentation patterns of the regioisomers of triacylglycerides obtained from different published datasets. We found the same qualitative trends of fragmentation beyond differences in the type of adduct in these datasets (both [M+NH4]+ and [M+H]+), and the type of instrument (orbitrap, Q-ToF, ion-trap, single quadrupole, and triple quadrupole). However, the quantitative trends of fragmentation were adduct and instrument specific. From these observations, we modeled quantitatively the common trends of fragmentation of triacylglycerides in every dataset. In a second step, we applied this methodology on a Synapt G2S Q-ToF to quantify the regioisomers of triacylglycerides in sunflower and olive oils. The results of our quantification were in good agreement with previous published quantifications of triacylglycerides, even for regioisomers that were not present in the training dataset. The species with more than two highly unsaturated fatty acids (arachidonic, eicosapentaenoic, and docosahexaenoic acids) showed a complex behavior and lower predictability of their fragmentation patterns. However, this framework presents the capacity to model this behavior when more data are available. It would be also applicable to standardize the quantification of the regioisomers of triacylglycerides in an inter-laboratory ring study.

Investigation of Drug-Packaging Interactions with Mass Spectroscopy Detectors: A Meta-Synthesis of the Literature

Abstract Background The production of hospital-compounded medicines with a longer shelf life raises questions about drug-packaging interactions, especially desorption events involving extractables and leachables (E/L). A meta-synthesis of the literature was performed to describe which mass spectrometer is suitable for identifying and quantifying E/L. Methods A meta-synthesis of studies focused on the identification or quantification of E/L published between January 1997 and December 2017 was performed. Inclusion criteria were E/L studies dealing with pharmaceutical products, in which mass spectrometry (MS) coupled to liquid chromatography (LC) or gas chromatography (GC) was used. The full-text articles had to be available and written in English. Articles about food packaging, environmental contamination, counterfeit compounds, pharmacokinetics, or process-related impurity studies were excluded. Two researchers independently assessed the papers according to a score based on a seven-item questionnaire. Results In total, 32 papers matched our criteria and were included in the meta-synthesis. For qualitative analysis with LC, quadrupole time-of-flight (QTOF; n=4) and ion trap (n=4) mass detectors were used the most; and with GC, single quadrupole (n=8). For quantification studies with LC, QTOF (n=3) and triple quadrupole (n=2) were used the most; and with GC, single quadrupole (n=7). Conclusions For simultaneous qualitative and quantitative analysis of E/L with LC, QTOF or Orbitrap is a suitable detector. For quantitative analysis with LC only, triple quadrupole is suitable. For qualitative and quantitative analysis with GC, single quadrupole can be used.

Optimization of lithium isotope analysis in geological materials by quadrupole ICP-MS

This study develops and optimizes a new method to measure lithium isotope ratios using a single collector quadrupole inductively coupled plasma mass spectrometer (Q-ICP-MS) operated under hot plasma (1550 W) conditions.

Direct analysis of radium-226 in sediment by ICP-MS: an analytical challenge?

Low levels of radium-226 were accurately measured in natural sediment digests using single quadrupole ICP-MS.

Rapid, direct, and sensitive determination of aziridine and 2-chloroethylamine by hydrophilic interaction liquid chromatography-mass spectrometry

A rapid HILIC-MS method was developed for measuring the genotoxic impurities aziridine and 2-chloroethylamine. Sample preparation was simple and direct without requiring derivatization. Paired with a 1.5 min isocratic UHPLC separation, sample analysis could be completed in less than 5 min. Linearity was established from 0.5 μg/L to 10 μg/L for both target analytes. For main components at 100 g/L, this equates to 5 parts per billion (ppb) detectability using a benchtop, single quadrupole detector. Three model matrices were evaluated (glycine, phenylalanine, and the pharmaceutical drug asunaprevir), and the method was able to provide suitable repeatability (<10% RSD) and accuracy (±10%) at 5 μg/L concentrations.•Direct sample preparation without derivatization as is needed for GC analyses•Less than 5 min required for sample preparation and HILIC-MS analysis•Part per billion sensitivity in multiple test matrices with good recovery

A simple and robust LC-ESI single quadrupole MS-based method to analyze neonicotinoids in honey bee extracts

Over the past years, neonicotinoids such as thiacloprid and flupyradifurone have gained considerable scientific and public interest. These molecules used as active compounds in pesticides are known due to cause drastic negative long-time effects on pollinators and even human health. Therefore, determining trace amounts of neonicotinoid in different environmental matrices by liquid chromatography coupled with mass selective detectors (LCMS/MS or LC-Q-TOF/MS) has become an important methodology. However, not every scientific group has unlimited access to high-resolution mass-selective detectors (e.g., MS/MS). It becomes more apparent that the analytics of neonicotinoids are already a global issue. Research groups and organizations with a limited financial budget often depend on using cheap and robust equipment to do their analytical work. We demonstrate a single-quadrupole (Q) MS-based method with single-class residue methods (SRMs) for the analysis of neonicotinoids, applicable without the requirement of a high-end MS system. For an adequate sample clean-up strategy, QuEChERS (Quick, Easy, Cheap, Efficient, Rugged, safe) extraction and purification methods were modified and applied to eliminate residual matrix after honey bee extraction steps to analyze thiacloprid and flupyradifurone.•Simple liquid chromatography electro-spray ionization (LC-ESI) single-quadrupole mass selective (MS) method for neonicotinoid analysis.•Efficient sample pretreatment by a modified QuEChERS extraction and purification method.•Limit of detection (LOD) and limit of quantification (LOQ) for thiacloprid was 19.72 ng g−1 and 7.61 ng g−1, for flupyradifurone 65.73 ng g−1 and 25.36 ng g−1, respectively.

Isolation of punicalagin from Punica granatum rind extract using mass-directed semi-preparative ESI-AP single quadrupole LC-MS

We are living in a era of alarming increases in microbial resistance to currently available antibiotics, and there is a growing need for new pharmaceutical products to treat infectious diseases. The pomegranate is an edible fruit that has virucidal and antimicrobial activities which is primarily attributable to the high concentration of hydrolysable tannins. Punicalagin, a high molecular weight tannin (1084.7), accounts for approximately 70% of the total and is concentrated in the fruit exocarp (rind). It is the focus of much research, although it is prohibitively expensive to purchase which presents an obstacle to further exploitation and development. Here we describe a method for the isolation of punicalagin from pomegranate rind extract and total pomegranate tannins using an Agilent preparative mass-directed LC–MS single quadrupole ESI-API system, where the ionization was set as negative and the mass signal acquired in Single Ion Monitoring. Thanks to the automatic fraction collector, the method can be used in automatic mode and is capable of producing punicalagin with >95% purity.

Direct speciation analysis of organophosphorus environmental pollutants in water by HPLC-ICPMS/MS

A new and optimized HPLC-ICPMS/MS method for the simultaneous determination of five of the most common phosphorous environmental pollutants in various water matrices has been developed, including aminomethylphosphonic acid (AMPA), glufosinate, glyphosate, fosamine, and ethephon. We show that the ICPMS/MS confers an average of 20-fold improvement in the detection limit (0.1–0.3 µg P L−1) relative to comparable methods based on single quadrupole ICPMS detection, without the incorporation of any sample purification or preconcentration step. The method was validated by determining the intra-day repeatability (< 6%), inter-day repeatability (< 10%) and recovery (86–112%) of 4 levels of spiking (5.0–250 µg L−1). The developed method involved utilizing the carbon enhancement effect which yielded up to 3-fold increase in sensitivity. A signal suppression effect exerted by the carbonate content of the analyzed water samples was identified, and should be generally taken into consideration when analyzing untreated hard water samples by HPLC-ICPMS. The developed method can be an important contribution in order to keep up with increasingly more stringent future regulations for the levels of the analyzed pollutants given their rising health concerns.

Quantification of malondialdehyde in exhaled breath condensate using pseudo two-dimensional ultra-performance liquid chromatography coupled with single quadrupole mass spectrometry

We developed a robust analytical method for quantification of malondialdehyde (MDA) in exhaled breath condensate (EBC) via derivatization with 2,4-dinitrophenylhydrazine (DNPH). The target MDA-DNPH hydrazone was separated by ultra-performance liquid chromatography using two reversed-phase analytical columns (C18 and phenyl-hexyl) inter-connected via a two-position, six-port switching valve to a single-quadrupole mass spectrometer. The target derivative was analyzed under positive electrospray ionization using single ion monitoring mode (m/z = 235 for the target derivative, and m/z = 237 for its labeled isotopic analog). This pseudo two-dimensional chromatographic separation provided optimum separation conditions for the target derivative resulting in the limit of detection of 0.58 nM in EBC sample (or 36.2 pmol on-column amount), which is comparable to those reported previously using different techniques, including tandem mass spectrometry. Based on the calibration solutions, the method had a linear quantification range of 1.0–200 nM (r2 = 0.998). The method showed good relative recoveries (92.2–102.0%) and acceptable precisions (3.6–12.2% for inter-day precision, and 4.3–12.4% for intra-day precision for two quality control levels, prepared from 5 nM and 25 nM solutions). The derivative was found to be stable at room temperature for 48 h or during analysis. The method was used to analyze 205 exhaled breath condensate samples collected from individuals from a healthy population of student athletes. MDA was detected in approximately 95% of these samples, with concentrations ranging from 1.16 to 149.63 nM. The median concentration was 6.82 nM, (IQR 4.08–9.88). These data demonstrate that our method can be successfully used to measure MDA in population studies.

Signals of diagnostic ions in the product ion spectra of [M - H]- ions of methoxylated flavonoids.

The main feature of the fragmentation of [M - H]- ions of methoxylated flavonoids is the loss of methyl radical (formation of the [M - H - CH3 ]-• product ion). Subsequent decomposition of [M - H - CH3 ]-• product ions may be useful for identification of a given compound by HPLC/MS. This paper describes how the selected diagnostic fragment ions can be useful during HPLC/MS(-) analysis of methoxylated flavonoids. Product ion spectra (ESI-CID-MS/MS spectra) of [M - H]- ions of 17 methoxylated flavonoids (flavones, isoflavones and flavonols) were obtained with a Q-TOF mass spectrometer. Full scan mass spectra (ESI-MS) were obtained with a single quadrupole type of instrument. A number of product ions were recognized as useful from the point of view of structural elucidation. In most cases they were diagnostic product ions, formed as a result of C ring breaking. The most important conclusions drawn from this study are: the product ion at m/z 132 indicates that the analysed compound is an isoflavone; the product ion at m/z 117 indicates the presence of one hydroxy group at ring B or at the 3-position; biochanin A and prunetin can be differentiated by their 'in-source' fragmentation, by the relative abundances of product ions at m/z 195, 183 and 167; loss of mass 102 from the [M - H - CH3 ]-• ion indicates that ring B is not substituted and there is no hydroxy group at the 3-position; and rhamnetin can be detected using three diagnostic product ions, namely at m/z 121, 165 and 193.

Determination of Humectants in Tobacco Filler by High Performance Chromatography/Single Quadrupole Mass Spectrometry.

Glycerol, and 1,2-propylene glycol are the humectants most commonly used by the tobacco industry. They are found in a variety of tobacco products and are often present at high levels (~2-5 % w/w). While humectants are generally considered safe, they may serve as precursors in the formation of harmful carbonyl compounds. A selective, precise, and sensitive method for the quantification of several humectants in cigarette filler was developed. The method's sample clean-up is a two-step process consisting of a mechanical extraction, followed by solid phase extraction. Individual humectants are separated, identified, and measured using liquid chromatography coupled to a single quadrupole mass spectrometer as the detector (LC/MS). Detection limits were 0.105, 0.575, and 0.039 mg/cigarette for glycerol, 1,2-propylene glycol and triethylene glycol, respectively. The quantification range for these analytes was 0.4-75.0 mg/cigarette. Twenty-seven brands of domestic commercial cigarettes were evaluated to assess typical levels of humectants in the tobacco filler.

Alternating-Phase Focusing for Dielectric-Laser Acceleration.

The concept of dielectric-laser acceleration provides the highest gradients among breakdown-limited (nonplasma) particle accelerators. However, stable beam transport and staging have not been shown experimentally yet. We present a scheme that confines the beam longitudinally and in one transverse direction. Confinement in the other direction is obtained by a single conventional quadrupole magnet. Within the small aperture of 420nm we find the matched distributions, which allow an optimized injection into pure transport, bunching, and accelerating structures. The combination of these resembles the photonics analogue of the radio frequency quadrupole, but since our setup is entirely two dimensional, it can be manufactured on a microchip by lithographic techniques. This is a crucial step towards relativistic electrons in the MeV range from low-cost, handheld devices and connects the two fields of attosecond physics and accelerator physics.

Implementation of a Single Quadrupole Mass Spectrometer for Fingerprint Analysis: Venenum bufonis as a Case Study.

The mass spectrometry (MS) has been widely used for profiling chemical components of traditional Chinese medicine (TCM). However, there are few studies reporting quality control of TCM based on mass spectrometry fingerprint (MSF) due to its complicated operation and high cost. The aim of this study was to extend the application of MSF for quality evaluation of TCM. In this study, an MSF based on single quadrupole mass spectrometry method was established, and was successfully used for the quality control of Venenum bufonis (VB), a famous TCM which was used clinically for cancer treatment in China. The results showed that the superiority of MSF for more chemical information exposure and the finding of more potential chemical markers (eight versus four) compared with the traditional photo-diode array (a kind of ultra violet detector, PDA). Besides, the performance of MSF was also validated by similarity and principle component analysis (PCA) of MS data acquired on two other mass spectrometry (low-resolution, triple quadrupole, QQQ, and high-resolution, quadruple time-of-flight, Q-TOF), showing high consistency with QQQ and Q-TOF, but robustness with few parameters’ settings. Based on our study, MSF could be widely applied for the quality control of TCM.

Comprehensive MS-based screening and identification of pharmaceutical transformation products formed during enzymatic conversion.

In this study, transformation products (TPs) of diclofenac, mefenamic acid, and sotalol derived from peroxidase- and laccase-catalyzed transformations were studied with different mass spectrometry (MS)-based workflows. A straightforward pre-screening of enzymatic degradation rate was performed using a robotic nano-ESI source coupled to single quadrupole MS. Accurate mass data and information on molecular hydrophobicity were obtained from a serial coupling of reversed phase liquid chromatography (RPLC) with hydrophilic interaction liquid chromatography (HILIC) to a time-of-flight-mass spectrometer (ToF-MS). These parameters were combined with fragmentation information from product ion scan operated in enhanced mode (EPI) with precursor selection in Q3 and data from multiple reaction monitoring (MRM) modes using a hybrid triple quadrupole-linear ion trap-mass spectrometer (QqQ/LIT-MS). "Suspect" MRM modes did not provide a significant sensitivity improvement compared to EPI experiments. The complementarity of the data from different MS-based workflows allowed for an increase of identification confidence. Overall, this study demonstrated that dimerization, hydroxylation, and dehydration reactions were the predominant mechanisms found for diclofenac and mefenamic acid during enzyme-catalyzed transformation, whereas a degradation product was observed for the peroxidase-catalyzed conversion of sotalol. Results can contribute to understand enzymatic mechanisms and provide a basis for assessing risks and benefits of enzyme-based remediation. Graphical abstract ᅟ.