Quadrupole Mass Spectrometer System Research Articles

Integration of targeted metabolome and transcript profiling of Pseudomonas syringae-triggered changes in defence-related phytochemicals in oat plants

Main conclusionA gene-to-metabolite approach afforded new insights regarding defence mechanisms in oat plants that can be incorporated into plant breeding programmes for the selection of markers and genes related to disease resistance.Monitoring metabolite levels and changes therein can complement and corroborate transcriptome (mRNA) data on plant–pathogen interactions, thus revealing mechanisms involved in pathogen attack and host defence. A multi-omics approach thus adds new layers of information such as identifying metabolites with antimicrobial properties, elucidating metabolomic profiles of infected and non-infected plants, and reveals pathogenic requirements for infection and colonisation. In this study, two oat cultivars (Dunnart and SWK001) were inoculated with Pseudomonas syringae pathovars, pathogenic and non-pathogenic on oat. Following inoculation, metabolites were extracted with methanol from leaf tissues at 2, 4 and 6 days post-infection and analysed by multiple reaction monitoring (MRM) on a triple quadrupole mass spectrometer system. Relatedly, mRNA was isolated at the same time points, and the cDNA analysed by quantitative PCR (RT-qPCR) for expression levels of selected gene transcripts associated with avenanthramide (Avn) biosynthesis. The targeted amino acids, hydroxycinnamic acids and Avns were successfully quantified. Distinct cultivar-specific differences in the metabolite responses were observed in response to pathogenic and non-pathogenic strains. Trends in aromatic amino acids and hydroxycinnamic acids seem to indicate stronger activation and flux through these pathways in Dunnart as compared to SWK001. A positive correlation between hydroxycinnamoyl-CoA:hydroxyanthranilate N-hydroxycinnamoyl transferase (HHT) gene expression and the abundance of Avn A in both cultivars was documented. However, transcript profiling of selected genes involved in Avn synthesis did not reveal a clear pattern to distinguish between the tolerant and susceptible cultivars.Graphical abstract

Quantification of parabens in marine fish samples by a rapid, simple, effective sample preparation method.

Parabens (p-hydroxybenzoic acid esters) commonly used preservatives (in cosmetics, pharmaceuticals, and foods) can pose potential effects on environmental health. In this study, seven parabens were quantified in marine fish samples using an ultra-high performance liquid chromatography triple quadrupole mass spectrometer (UHPLC-MS/MS) system. Parabens in the fish samples were extracted and purified by a rapid, simple, and effective procedure comprising sample homogenization with solvent, solid-phase extraction clean-up, and solvent evaporation. Results demonstrated that the recoveries of seven compounds (with relative standard deviation < 15%) were 88-103% in matrix-spike samples and 86-105% in surrogate standards. The method detection limits and method quantification limits of seven parabens were 0.015-0.030 and 0.045-0.090ng/g-ww (wet weight), respectively. The optimized method was applied to measure the concentration of parabens in the 37 marine fish samples collected from Vietnam coastal waters. The concentration ranges of seven parabens found in round scad and greater lizardfish samples were 6.82-25.3ng/g ww and 6.21-17.2ng/g-ww, respectively. Among parabens, methylparaben accounted for the highest contribution in both fish species (43.2 and 44.9%, respectively). Based on the measured concentrations of parabens in marine fish samples, the estimated daily intake was calculated for children and adults with the corresponding values of 0.0477µg/kg/day and 0.0119µg/kg/day, respectively. However, the presence of parabens in Vietnamese marine fish may not pose a significant risk to human health.

A robust LC-MS/MS method to measure 8-oxoGuo, 8-oxodG, and NMN in human serum and urine

ObjectiveTo establish and validate a robust LC-MS/MS method for simultaneously measuring 8-oxoGuo, 8-oxodG, and NMN in serum and urine to evaluate the oxidative stress status. MethodsA Waters TQ-XS triple quadrupole mass spectrometer system coupled with an Acquity UPLC Primer HSS T3 column was chosen. The clinical performance was verified according to the CLSI C62-A and EP-15 guidelines. Furthermore, matched serum and urine samples from 22 apparently healthy check-ups, 20 patients with atherosclerosis, and 18 individuals with dementia were evaluated. ResultsThe recovery for serum 8-oxoGuo, urine 8-oxoGuo, serum 8-oxodG, urine 8-oxodG, serum NMN, and urine NMN was 88.8–112.4%, 102.4–114.1%, 88.5–107.7%, 94.9–102.6%, 98.4–108.9%, and 88.5–108.6%, respectively. Based on the inter-assay results, total coefficient of variation, matrix effect, and carryover, the LC-MS/MS method was deemed robust. The limit of quantification was 0.017, 0.018, and 0.150 nmol/L for 8-oxoGuo, 8-oxodG, and NMN, respectively, which are suitable for accurate measurements in human serum and urine samples. Higher 8-oxoGuo and 8-oxodG levels and lower NMN levels, indicative of significantly higher oxidative stress status, were found in patients with dementia compared to healthy subjects. ConclusionWe established and validated a robust LC-MS/MS method to simultaneously measure 8-oxoGuo, 8-oxodG, and NMN in serum and urine.

Analytical scaling of Quadrupole Mass Spectrometer for Point of Care Applications

The best way to combat a disease is its early detection. A low-cost portable point of care (POC) device is required for early disease detection. A mass spectrometer (MS) is a golden analytical technique to diagnose many diseases. Conventional mass spectrometers are bulky and costly and limited to expensive laboratory setups. In the present paper, a POC-type quadrupole mass spectrometer (QMS) system is proposed for the early detection of diseases. The main component of QMS that makes it bulky and costly is the vacuum system. The length of the quadrupole filter determines its resolution, and the vacuum level is a function of its length. Hence, both length and vacuum levels are optimized without compromising resolution. The size of the quadrupole rods is reduced to 26 mm at 0.1 pascal pressure for portable applications. This optimized QMF is designed and simulated in COMSOL Multiphysics. The system's vacuum level is designed so that a single rotary pump can serve the purpose without any turbopump. A closed-form expression for mass resolution, pressure, and frequency is also derived.

A Dilute-and-Shoot LC-MS/MS Method for Screening of 43 Cardiovascular Drugs in Human Urine

A simple, specific, and economical LC-MS/MS method was investigated for the screening of 43 prescribed antihypertensive and related drugs in human urine. The urine samples were simply prepared by diluting and mixing with internal standard before directly introduced to the LC-MS/MS system, which is fast, straightforward, and cost-effective. Fractional factorial, Box-Behnken, and I-optimal design were applied to screen and optimize the mass spectrometric and chromatographic factors. The analysis was carried out on a triple quadrupole mass spectrometer system utilizing multiple reaction monitoring with positive and negative electrospray ionization method. Chromatographic separation was performed on a Thermo Scientific Accucore RP-MS column (50 × 3.0 mm ID., 2.6 μm) using two separate gradient elution programs established with the same mobile phases. Chromatographic separation was performed within 12 min. The optimal method was validated based on FDA guideline. The results indicated that the assay was specific, reproducible, and sensitive with the limit of detection from 0.1 to 50.0 μg/L. The method was linear for all analytes with coefficient of determination ranging from 0.9870 to 0.9981. The intra-assay precision was from 1.44 to 19.87% and the inter-assay precision was between 2.69 and 18.54% with the recovery rate ranges from 84.54 to 119.78% for all drugs measured. All analytes in urine samples were stable for 24 h at 25℃, and for 2 weeks at -60℃. The developed method improves on currently existing methods by including larger number of cardiovascular medications and better sensitivity of 12 analytes.

Residual gas analysis in vacuum insulation panel (VIP) with glass fiber core and investigation of getter for VIP

Vacuum insulation panel (VIP) based on glass fiber core material has attracted considerable attention in building insulation due to lower core material cost than fumed silica. The insulation performance and service life of VIP are significantly dependent on the residual gas pressure and gas composition in VIP. Residual gas composition is measured using a newly-developed test apparatus that contains quadrupole mass spectrometer (QMS) and gas inlet system (GIS) in this paper. The results indicate that the main residual gases are nitrogen (N2), oxygen (O2) and water vapor (H2O) in the initial stage of VIP with thermal conductivity 1.52 mW m−1 K−1, while nitrogen (N2), oxygen (O2) hydrogen (H2) and water vapor (H2O) become the main residual gases after two years with thermal conductivity 6.80 mW m−1 K−1. Correspondingly, a composite getter for VIP is investigated, sorption capacities of which for hydrogen (H2), oxygen (O2) and water vapor (H2O) are measured in this paper. It is predicted that the central thermal conductivity of VIP with getter increases to 15 mW m−1 K−1 after 25 years, which is one step towards a future recommendation for building sectors.

Density stratification breakup by a vertical jet: Experimental and numerical investigation on the effect of dynamic change of turbulent schmidt number

The hydrogen behavior in a nuclear containment vessel is one of the significant issues raised when discussing the potential of hydrogen combustion during a severe accident. Computational Fluid Dynamics (CFD) is a powerful tool for better understanding the turbulence transport behavior of a gas mixture, including hydrogen. Reynolds-averaged Navier–Stokes (RANS) is a practical-use approach for simulating the averaged gaseous behavior in a large and complicated geometry, such as a nuclear containment vessel; however, some improvements are required. In this paper, we focused on the turbulent Schmidt number Sct for improving the RANS accuracy. Some previous studies on ocean engineering mentioned that the Sct value gradually increases with the increasing stratification strength. We implemented the dynamic modeling for Sct based on the previous studies into the OpenFOAM ver 2.3.1 package. The experimental data obtained by using a small scale test apparatus at Japan Atomic Energy Agency (JAEA) was used to validate the RANS methodology. In the experiment, we measured the velocity field around the interaction region between vertical jet and stratification by using the Particle Image Velocimetry (PIV) system and time transient of gas concentration by using the Quadrupole Mass Spectrometer (QMS) system. Moreover, Large-Eddy Simulation (LES) was performed to phenomenologically discuss the interaction behavior. The comparison study indicated that the turbulence production ratio by shear stress and buoyancy force predicted by the RANS with the dynamic modeling for Sct was a better agreement with the LES result, and the gradual decay of the turbulence fluctuation in the stratification was predicted accurately. The time transient of the helium molar fraction in the case with the dynamic modeling was very closed to the VIMES experimental data. The improvement on the RANS accuracy was produced by the accurate prediction of the turbulent mixing region, which was explained with the turbulent helium mass flux in the interaction region. Moreover, the parametric study on the jet velocity indicates the good performance of the RANS with the dynamic modeling for Sct on the slower erosive process. This study concludes that the dynamic modeling for Sct is a useful and practical approach to improve the prediction accuracy.

Determination of Volatile Fuel Oxygenates in Water by Gas Chromatography–Triple Quadrupole Mass Spectrometry: Effect of Automated Sample Preparation Techniques

Considering the adverse effects of gasoline additives and aromatic compounds on the quality of the water supply and the ecological environment of the water, a methodology, with short chromatographic separation time (22.5 min) and high separation quality, was optimized for the determination of 11 common gasoline additives and aromatic compounds using gas chromatograph coupled with triple quadrupole mass spectrometer (GC–QqQ–MS/MS) system. The extraction procedure of analytes was performed by headspace solid–phase microextraction (HS–SPME) and purge and trap (P&amp;T), respectively. Both of the two extraction methods provided excellent chromatographic resolution in subsequently GC–QqQ–MS/MS detection system, with the coefficients of linear regression of the calibration curves with HS–SPME and P&amp;T pretreatments were 0.9965~0.9998 and 0.9961~0.9999, respectively, n = 7. The limit of detections (LODs) of these selected oxygenate compounds were discovered to be 0.52~32 ng/L in the P&amp;T–GC–QqQ–MS/MS detection system and 0.11~151 ng/L in the HS–SPME–GC–QqQ–MS/MS detection system. For benzene, toluene, ethylbenzene and xylene isomers (BTEX), the HS–SPME–GC–QqQ–MS/MS system provided outstanding detection performance because of the lower LOD obtained. However, for other selected compounds, the P&amp;T–GC–QqQ–MS/MS system offered lower LODs. The proposed extraction–detection procedure is a simple and sensitive analytical approach for the detection of gasoline additives and aromatic compounds in water.

Development, validation and evaluation of a quantitative method for the analysis of twenty-four new psychoactive substances in oral fluid by LC–MS/MS

The use of new psychoactive substances (NPS) has been recognized worldwide at an alarming rate. Oral fluid collection is becoming more prevalent as a matrix for evaluating drug consumption. In this study, a specific, quick and non-invasive method for detection and quantitation of twenty-four synthetic cannabinoids and cathinone derivatives, including ten not previously reported NPS in oral fluid was performed. A quantitative method was developed on a liquid chromatography coupled to a triple quadrupole mass spectrometer system operated in dynamic multiple reaction monitoring (dMRM) mode using solid phase extraction (SPE) as pre-concentration step. Analytical separation of the target drugs was reached in a total elution time of 10 min. The developed method was validated according to the ASB standard 036. Overall bias and precision of the method were within ±20% for twenty-three compounds. All drugs showed acceptable linearity with R2 values greater than 0.98, and LLOQ values of 0.25 ng/mL and 1.0 ng/mL for selected NPS. The overall bias for a performed blind verification study was 7%. Our results demonstrate the method is suitable for quantifying NPS in oral fluid through solid phase extraction and analysis using LC–MS/MS.

Small Quadrupole Mass Spectrometer System and Its Applications

Small Quadrupole Mass Spectrometer System and Its Applications

Quantification of metronidazole in human plasma using a highly sensitive and rugged LC-MS/MS method for a bioequivalence study.

A highly sensitive, selective and rugged method has been described for the quantification of metronidazole (MTZ) in human plasma by liquid chromatography-tandem mass spectrometry using metronidazole-d4 as the internal standard (IS). The analyte and the IS were extracted from 100 μL plasma by liquid-liquid extraction. The clear samples obtained were chromatographed on an ACE C18 (100 × 4.6 mm, 5 μm) column using acetonitrile and 10.0 mm ammonium formate in water, pH 4.00 (80:20, v/v) as the mobile phase. A triple quadrupole mass spectrometer system equipped with turbo ion spray source and operated in multiple reaction monitoring mode was used for the detection and quantification of MTZ. The calibration range was established from 0.01 to 10.0 μg/mL. The results of validation testing for precision and accuracy, selectivity, matrix effects, recovery and stability complied with current bioanalytical guidelines. A run time of 3.0 min permitted analysis of more than 300 samples in a day. The method was applied to a bioequivalence study with 250 mg MTZ tablet formulation in 24 healthy Indian males.

A nontargeted screening method for covalent DNA adducts and DNA modification selectivity using liquid chromatography-tandem mass spectrometry

A method for nontargeted screening for covalent DNA adducts was developed using combination of neutral loss scan and product ion scan in a hybrid linear-ion-trap - triple quadrupole mass spectrometer system. DNA 2′-deoxynucleosides and adducts eluted from liquid chromatography were first analyzed in neutral loss mode to screen for the neutral loss of the deoxyribose moiety ([M+H-116]+) from the protonated molecular ion ([M+H]+). The product ion scan was subsequently used to elucidate the structures for the molecular ions observed from the peaks in the neutral loss scan chromatogram. The synthesized DNA adducts were used to evaluate the developed method by reaction of 20-mer DNA oligonucleotide with two direct agents respectively, specifically phenyl glycidyl ether and styrene-7,8-oxide. The modification selectivity of two compounds to the four nitrogenous bases on DNA sequence was also investigated in this study. The results showed that the two compounds had different modification selectivity to the four bases. Both compounds could modify all four nitrogenous bases (i.e. adenine, guanine, thymine, and cytosine) on DNA sequences to form various covalent DNA adducts. While phenyl glycidyl ether modified almost all of thymidine on DNA sequence, styrene-7,8-oxide, on the other hand, modified only a small portion of thymidine. The developed method proved possibly a potential tool for screening of unknown DNA adducts as exposure biomarkers of contaminants to human in the environment.

Experimental and numerical study on density stratification erosion phenomena with a vertical buoyant jet in a small vessel

The Japan Atomic Energy Agency (JAEA) has started the ROSA-SA project to investigate thermal hydraulic phenomena in a reactor containment vessel during a severe accident. The hydrogen distribution in the vessel is one of significant safety issues in discussing a potential of hydrogen combustion in the containment. Density stratification and its break-up are important phenomena affecting the hydrogen distribution. This paper focuses on a density stratification erosion and break-up mechanism with a vertical buoyant jet promoting the turbulent helium transport. Small scale experiment and computational fluid dynamics (CFD) analyses were carried out for investigating this phenomena. In the experiment, a rectangular vessel made with acrylic plates with a width of 1.5m, a length of 1.5m and a height of 1.8m was used for visualizing flow field with particle image velocimetry (PIV) system. The quadrupole mass spectrometer (QMS) system with a multiport rotating valve was applied for measuring gaseous concentration at 20 elevation points. In CFD analysis with OpenFOAM, two typical well-used turbulence models were used: low-Reynolds number type k–ɛ model and SST k–ω model, with a turbulence model modification to consider the buoyant effect in the stratification. As a result, the stratification erosion in the CFD analyses with the modified turbulence model agreed well with the experimental data, indicating importance of the turbulence damping by the buoyant effect.

Diagnosis of Helicobacter pylori by carbon-13 urea breath test using a portable mass spectrometer.

Context:In the non-invasive detection of markers of disease, mass spectrometry is able to detect small quantities of volatile markers in exhaled air. However, the problem of size, expense and immobility of conventional mass spectrometry equipment has restricted its use. Now, a smaller, less expensive, portable quadrupole mass spectrometer system has been developed. Helicobacter pylori has been implicated in the development of chronic gastritis, gastric and duodenal ulcers and gastric cancer.Objectives:To compare the results obtained from the presence of H. pylori by a carbon-13 urea test using a portable quadrupole mass spectrometer system with those from a fixed mass spectrometer in a hospital-based clinical trial.Methods:Following ethical approval, 45 patients attending a gastroenterology clinic at the Royal Liverpool University Hospital exhaled a breath sample into a Tedlar gas sampling bag. They then drank an orange juice containing urea radiolabelled with carbon and 30 min later gave a second breath sample. The carbon-13 content of both samples was measured using both quadrupole mass spectrometer systems. If the post-drink level exceeded the pre-drink level by 3% or more, a positive diagnosis for the presence of H. pylori was made.Results:The findings were compared to the results using conventional isotope ratio mass spectrometry using a laboratory-based magnetic sector instrument off-site. The results showed agreement in 39 of the 45 patients.Conclusions:This study suggests that a portable quadrupole mass spectrometer is a potential alternative to the conventional centralised testing equipment. Future development of the portable quadrupole mass spectrometer to reduce further its size and cost is indicated, together with further work to validate this new equipment and to enhance its use in mass spectrometry diagnosis of other medical conditions.

Experimental investigation of the 2D ion beam profile generated by an ESI octopole-QMS system.

In this paper, we have employed an ion imaging approach to investigate the behavior of ions exiting from a quadrupole mass spectrometer (QMS) system that employs a radio frequency octopole ion guide before the QMS. An in-vacuum active pixel detector (Timepix) is employed at the exit of the QMS to image the ion patterns. The detector assembly simultaneously records the ion impact position and number of ions per pixel in every measurement frame. The transmission characteristics of the ion beam exiting the QMS are studied using this imaging detector under different operating conditions. Experimental results confirm that the ion spatial distribution exiting the QMS is heavily influenced by ion injection conditions. Furthermore, ion images from Timepix measurements of protein standards demonstrate the capability to enhance the quality of the mass spectral information and provide a detailed insight in the spatial distribution of different charge states (and hence different m/z) ions exiting the QMS.

High-Throughput Operando Raman–Quadrupole Mass Spectrometer (QMS) System to Screen Catalytic Systems

This paper describes the design and setup of a high-throughput Raman system for an array of eight parallel catalytic reactors during reaction conditions. The "operando" methodology combines in situ spectroscopy during catalytic reaction with a simultaneous activity measurement. The high-throughput operando Raman system, multi-operando, is a device that automates this operando methodology for several catalyst samples at the same time, all samples being in the same reaction conditions. We describe how the system is made, how Raman system positions and acquires spectra, and how each reactor outlet gas is selected and analyzed.

Pseudo-MS3Approach Using Electrospray Mass Spectrometry (ESI-MS/MS) to Characterize Certain (2E)-2-[3-(1H-Imidazol-1-yl)-1-phenylpropylidene]hydrazinecarboxamide Derivatives

An approach for the use of in-source fragmentation with electrospray ionization followed by product ion scan in a triple quadrupole mass spectrometer system is described. This approach is based on the elucidation of the various fragmentation pathways by further dissociation of each fragment ion in the ion spectrum. This can be achieved predominately, by combining fragmentor voltage induced dissociation (in-source fragmentation) with subsequent collision-induced dissociation; this process can be referred to as pseudo-MS3scan mode. This technique permitted unambiguous assignment and provided sufficient sensitivity and specificity. It is advantageous for structure elucidation of unknown compounds. We investigate the possibility of using in-source fragmentation with the diverse novel chemical entities encompassing different substituents. This process was intended to improve the qualitative capability of tandem mass spectrometry simulating the MS3of ion trap for studying fragmentation mechanisms. The approach is to implement the investigated technique as a well established tool for the characterization of new pharmacologically important chemical entities. The data presented in this paper provided useful information on the effect of different substituents on the ionization/fragmentation processes and can be used in the characterization of (2E)-2-[3-(1H-imidazol-1-yl)-1-phenylpropylidene]-hydrazinecarboxamide derivatives3a–h.

Multistage Fragmentation of Ion Trap Mass Spectrometry System and Pseudo-MS3of Triple Quadrupole Mass Spectrometry Characterize Certain (E)-3-(Dimethylamino)-1-arylprop-2-en-1-ones: A Comparative Study

A new approach was recently introduced to improve the structure elucidation power of tandem mass spectrometry simulating the MS3 of ion trap mass spectrometry system overcoming the different drawbacks of the latter. The fact that collision induced dissociation in the triple quadrupole mass spectrometer system provides richer fragment ions compared to those achieved in the ion trap mass spectrometer system utilizing resonance excitation. Moreover, extracting comprehensive spectra in the ion trap needs multistage fragmentation, whereas similar fragment ions may be acquired from one stage product ion scan using the triple quadrupole mass spectrometer. The new strategy was proven to enhance the qualitative performance of tandem mass spectrometry for structural elucidation of different chemical entities. In the current study we are endeavoring to prove our hypothesis of the efficiency of the new pseudo-MS3 technique via its comparison with the MS3 mode of ion trap mass spectrometry system. Ten pharmacologically and synthetically important (E)-3-(dimethylamino)-1-arylprop-2-en-1-ones (enaminones 4a–j) were chosen as model compounds for this study. This strategy permitted rigorous identification of all fragment ions using triple quadrupole mass spectrometer with sufficient specificity. It can be used to elucidate structures of different unknown components. The data presented in this paper provide clear evidence that our new pseudo-MS3 may simulate the MS3 of ion trap spectrometry system.

Low energy electron attachment to platinum(II) bromide (PtBr2)

Dissociative electron attachment to PtBr2 in the gas phase was studied in the low electron energy range from zero up to 10eV with an energy resolution of 150meV. The experiments were carried out using a hemispherical electron monochromator coupled with a quadrupole mass spectrometer and pulse counting acquisition system. The only anion observed was Br−. This ion is formed at three resonance electron energies: 0.4eV, 1.2eV and 7eV. By the measurements of the Br− formation at different sample temperatures (in the 350–430K range) the 0.4eV resonance was associated with the electron capture by HBr generated in the apparatus at elevated temperatures. In addition, the thermodynamic thresholds for dissociative electron attachment reactions for platinum(II) bromide were calculated and compared with the experimental results.

Microfluidic chip-based nano-liquid chromatography tandem mass spectrometry for quantification of aflatoxins in peanut products

Aflatoxins (AFs), a group of mycotoxins, are generally produced by fungi Aspergillus species. The naturally occurring AFs including AFB1, AFB2, AFG1, and AFG2 have been clarified as group 1 human carcinogen by International Agency for Research on Cancer. Developing a sensitive analytical method has become an important issue to accurately quantify trace amount of AFs in foodstuffs. In this study, we employed a microfluidic chip-based nano LC (chip-nanoLC) coupled to triple quadrupole mass spectrometer (QqQ-MS) system for the quantitative determination of AFs in peanuts and related products. Gradient elution and multiple reaction monitoring were utilized for chromatographic separation and MS measurements. Solvent extraction followed by immunoaffinity solid-phase extraction was employed to isolate analytes and reduce matrix effect from sample prior to chip-nanoLC/QqQ-MS analysis. Good recoveries were found to be in the range of 90.8%−100.4%. The linear range was 0.048−16ngg−1 for AFB1, AFB2, AFG1, AFG2 and AFM1. Limits of detection were estimated as 0.004−0.008ngg−1. Good intra-day/inter-day precision (2.3%−9.5%/2.3%−6.6%) and accuracy (96.1%−105.7%/95.5%−104.9%) were obtained. The applicability of this newly developed chip-nanoLC/QqQ-MS method was demonstrated by determining the AFs in various peanut products purchased from local markets.