Performance Liquid Chromatography-triple Quadrupole Mass Research Articles

Determination of phenolic compounds in olive oil: New method based on liquid–liquid micro extraction and ultra high performance liquid chromatography-triple–quadrupole mass spectrometry

A novel analytical approach has been performed and evaluated for the identification and quantification of phenolic compounds (phenolic alcohols, secoiridoid derivates, lignans, flavonoids, phenolic acids and aldehydes) which can be found in both virgin olive oil (VOO) and extra virgin olive oil (EVOO). An improved liquid–liquid micro extraction (LLME) method combining with ultra high performance liquid chromatography (UHPLC) coupled to electrospray ionization source (ESI) and tandem mass spectrometry (MS/MS) in Dynamic Multiple Reaction Monitoring (DMRM) mode has been developed, reducing the amount of sample, reagents and time consumed. The proposed methodology was applied to standard solutions, and the quality control parameters obtained were compared with those achieved in spiked refined olive oil (SROO). Generally, these parameters showed lower values in SROO than in standard solutions. Matrix effect, recovery and process efficiency have been studied using SROO. The recoveries were around 90% and the process efficiency of the whole method was higher than 80% for most of the phenolic compounds studied. Examination of these parameters revealed that work straight in the olive oil matrix, which is closer to behave as a real sample, provides better results. The applicability and reliability of this methodology have been confirmed using real samples.

Simultaneous determination and screening of five pigments in marine phytoplanktons by high performance liquid chromatography-triple quadrupole mass spectrometry

A quantitative method based on high performance liquid chromatography coupled with electrospray ionization tandem triple-quadrupole mass spectrometry (HPLC-ESI-QqQ-MS) has been established for five pigments in marine phytoplanktons. The HPLC method used ternary solvent systems and a reversed-phase C16-amide column. In addition, methanol, acetonitrile and aqueous ammonium acetate were used as mobile phases. Five pigments (chlorophyll a, chlorophyll b, β, β-carotene, lutein and fucoxanthin) were quantified in selective reaction mode. As results, good linear relationships were achieved between the concentrations and the peak areas of the five pigment standards. And their correlation coefficients (r2) were higher than 0.996. The recoveries of the pigment standards were between 82.77% and 99.83%. The inter-day and intra-day precisions were lower than 5% (n = 5). The detection limits of the pigments for this method were between 0.02 and 0.16 μg/L and the quantification limits were in the range from 0.06 to 0.54 μg/L. According to the above method, eleven algae (Heterosigma akashiwo (NMBRah03-2), Heterosigma akashiwo (NMBRah03-2-2), Karlodinium veneficum (NMBjah047-1), Prorocentrum minimum ( NMBjah042), Nannochloropsis oceanic (NMBluh014), Chlorella pyrenoidosa (NMBluh015-1), Pleurochrysis sp. (NMBjih026-1), Prymnesium sp. (NMBjih029), Skeletonema costatum (NMBguh004-1), Thalassiosira weiss- flogii (NMBguh021) and Thalassiosira pseudonana) (NMBguh005)) have been investigated for comparing the pigment distributions. The method is sensitive, accurate, reproducible, and useful for the study of alga compositions.

Simultaneous determination of ten phytohormones in five parts of Sargasum fusiforme (Hary.) Seichell by high performance liquid chromatography-triple quadrupole mass spectrometry

A method for the simultaneous determination of indole-3-acetic acid, N6-(2-isopentenyl) adenosine, N6-(2-isopentenyl) adenine, trans-zeatin riboside, zeatin, strigolactone, abscisic acid, salicylic acid, gibberellin A3 and jasmonic acid in five different parts of main branch, lateral branch, primary leaf, secondary leaf and stem of Sargasum fusiforme (Hary.) Seichell was established by high performance liquid chromatography-triple quadrupole mass spectrometry (HPLC-TQMS). The samples were extracted with methanol/water/formic acid (15 : 4 :1, v/v/v) (containing 0.5% 2, 6-di-tert-butyl-4-methylphenol, BHT) after vacuum freeze-drying. The separation was performed on a Hypersil Gold C18 column by using methanol and water as mobile phases with gradient elution. The analytes were detected by tandem mass spectrometry in selected reaction monitoring (SRM) mode. The electrospray ionization (ESI) source was used for the quantitative analysis in the positive mode or negative mode. Under the optimized conditions, the correlation coefficients (r) of the ten phytohormones were from 0. 9989 to 1. 0000 in the linear ranges. The detection limits of the ten phytohormones were 0. 001 2-4. 651 2 μ/L. The average recoveries were 72. 24% -91. 31% with the relative standard deviations not more than 6. 59%. In the five parts of fresh Sargasum fusiforme (Hary.) Seichell samples, the contents of the ten phytohormones were from not detected to 4 041. 431 ng/g. This method has good sensitivity, precision, recovery, and can be used to simultaneously determine the phytohormones.

Determination of phenylethanolamine A residue in feeds by ultra performance liquid chromatography-tandem mass spectrometry

A method was developed for the determination of the residue of phenylethanolamine A in feeds by ultra performance liquid chromatography-triple quadrupole mass spectrometry (UPLC-MS/MS). The phenylethanolamine A in sample was extracted with phosphoric acid methanol solution. The extract was purified and concentrated by an MCX column. In the positive mode, an ultra-performance BEH C18 column (100 mm x 2.1 mm, 1.7 microm) was used to separate the phenylethanolamine A, and the separation was carried out on a Waters UPLC system by using gradient elution with acetonitrile and 0.1% (v/v) formic acid aqueous solution as the mobile phases at a flow rate of 0.4 mL/min. The qualitative and quantitative analysis was carried out by multi-reaction monitoring (MRM) mode, in which the analyte was ionized by electrospray ionization interface (ESI). The results showed that, the calibration curve was linear in the range of 0.5-100 microg/kg (r > 0.999), the limit of quantification (S/N > 10) was 10 microg/kg, the recoveries ranged from 79.6% to 86.2%, and the relative standard deviations (RSDs) were between 3.1% and 6.7%. The real sample tests showed that the method is convenient and reliable.

Rapid Quantification of Cereulide, Emetic Toxin of Bacillus Cereus, in Foods by Ultra Performance Liquid Chromatography-Triple Quadrupole Mass Spectrometry

Rapid Quantification of Cereulide, Emetic Toxin of Bacillus Cereus, in Foods by Ultra Performance Liquid Chromatography-Triple Quadrupole Mass Spectrometry

Assessment of the effects of Radix Bupleuri and vinegar-baked Radix Bupleuri on cytochrome 450 activity by a six-drug cocktail approach

AimTo assess the effects of Radix Bupleuri and vinegar-baked Radix Bupleuri on cytochrome 450 activity of rats. MethodsSix probe drugs (caffeine, midazolam, dextromethorphan, tolbutamide, omeprazole, chlorzoxazone) were simultaneously given to rats after different dosing of Radix Bupleuri or vinegar-baked Radix Bupleuri for seven days. The plasma concentrations of the six probes were measured by high performance liquid chromatography-triple quadrupole mass spectrometry (HPLC-MS/MS) and their corresponding pharmacokinetic parameters were calculated. ResultsThe AUC and T1/2 of midazolam, dextromethorphan and chlorzoxazone decreased significantly (P < 0.05) in rats after different dosing of Radix Bupleuri or vinegar-baked Radix Bupleuri for seven days. Treatment of Radix Bupleuri decreased T1/2 and AUC of omeprazole, but treatment of vinegar-baked Radix Bupleuri with normal dose did not change the pharmacokinetics of omeprazole. The pharmacokinetics of tolbutamide in all vinegar-baked Radix Bupleuri-treated rats showed no statistically significant difference (P > 0.05) from that of controlled rats, however, treatment of Radix Bupleuri decreased tolbutamide T1/2. The pharmacokinetics of caffeine in all Radix Bupleuri or vinegar-baked Radix Bupleuri-treated rats showed no statistically significant difference (P > 0.05) from that of controlled rats. ConclusionThe Radix Bupleuri and vinegar-baked Radix Bupleuri have different effects on the CYP2C9 and CYP2C19. Radix Bupleuri and vinegar-baked Radix Bupleuri have strong induction effects on the CYP2E1, CYP2D6 and CYP3A4, however, have no impact on CYP1A2. The reason of different therapeutic effects of Radix Bupleuri and vinegar-baked Radix Bupleuri extract may be the different effects of Radix Bupleuri and vinegar-baked Radix Bupleuri on the CYP2C9 and CYP2C19.

Determination of tetrodotoxin in seafood using graphitized carbon black clean-up with hilic ultra performance liquid chromatography-triple quadrupole mass spectrometry

To develop a rapid hilic ultra performance liquid chromatography (UPLC)-mass spectrum (MS)/MS method for determination of tetrodotoxin in seafood. The sample of muscle and liver of puffer fish and nassarius were extracted with aqueous solution containing 0.2% (V/V) acetic acid (the extract of liver must be purified through HLB cartridge), and then cleanup of extract was accomplished by solid-phase extraction with a graphitized carbon black cartridge. The analysis of tetrodotoxin was carried out on a chromatographic column (Acquity UPLC BEH Amide, 100 mm×2.1 mm×1.7 µm) with gradient elution of 95% (V/V) acetonitrile-H2O both containing 0.1% (V/V) formic acid and 2.0 mmol/L ammonium formate, and detected by positive electrospray ionization tandem mass spectrometry in the multiple reaction monitoring (MRM) mode, and quantified by matrix-match standard solution. The calibration curves were linear in the range of 30 - 10 000, 50 - 10 000 and 30 - 10 000 µg/kg of tetradotoxin in muscle and liver of puffer fish and in muscle of nassarius, respectively. The correlation coefficients were within 0.9963 - 0.9990. The limits of detection were 10, 20 and 10 µg/kg, and that of quantitation were 30, 50 and 30 µg/kg for muscle and liver of puffer fish and muscle of nassarius, respectively. The average recoveries were 81.5% - 93.1%, 82.3% - 106.0% and 83.5% - 95.2% for tetrodotoxin spiked in muscle and liver of puffer fish and in muscle of nassarius, respectively, with relative standard deviation (RSD) of 2.3% - 11%, 4.3% - 14.0% and 3.5% - 13.0% (n = 6). The method was simple, accurate and sensitive, and could be successfully applied to the measurement of tetrodotoxin in puffer fish and nassarius.

Simultaneous determination of five Amadori compounds in tobacco by high performance liquid chromatography-mass spectrometry

A method of high performance liquid chromatography-triple quadrupole mass spectrometry (HPLC-QqQ MS) in multiple reaction monitoring (MRM) mode for simultaneous determination of five Amadori compounds in tobacco has been developed. The separation was performed on an XBridge Amide column (250 mm x 4.6 mm, 3.5 microm) by gradient elution using methanol and water as mobile phases. The linearity of this method was good with the correlation coefficients (r) of 0.9895-0.9989. The limits of detection (S/N = 3) were from 3.51 microg/L to 14.86 microg/L, and the limits of quantitation (S/N = 10) were from 10.18 microg/L to 44.58 microg/L. The recoveries varied from 92.6% to 123.6% with the relative standard deviations (RSDs) less than 9.4%. The established method is rapid, accurate, robust and convenient, and it could be applied to the measurement of the five Amadori compounds in tobacco and cigarettes.

Simple, Rapid, and Simultaneous Assay of Multiple Carboxyl Containing Phytohormones in Wounded Tomatoes by UPLC-MS/MS Using Single SPE Purification and Isotope Dilution

An efficient simplified isotope dilution method was developed to determine four carboxyl containing phytohormones simultaneously in 200 mg of fresh tomato tissues using ultra high performance liquid chromatography-triple quadrupole mass spectrometry (UPLC-MS/MS) with negative electrospray ionization. The four phytohormones are indole-3-acetic acid (IAA), abscisic acid (ABA), jasmonic acid (JA), and salicylic acid (SA). Only one purification step of Oasis MAX solid phase extraction (SPE) was employed to enrich target phytohormones after crude extraction. In addition, two endogenous isomers of JA, (-)-JA and (+)-7-iso-JA, were separated directly. The validated method has been applied to monitor changes of JA, SA, IAA, and ABA in both local and systemic leaves of wild-type and transgenic 35S::prosystemin (35S::PS) tomato lines. Meanwhile, the JA burst amplified by the overexpressed prosystemin in 35S::PS was verified. Furthermore, the spatial and temporal changes of JA, SA, ABA, and IAA were analyzed.

Hollow fiber-based liquid–liquid–liquid micro-extraction with osmosis: II. Application to quantification of endogenous gibberellins in rice plant

The phenomenon and benefits of osmosis in hollow fiber-based liquid–liquid–liquid micro-extraction (HF-LLLME) were theoretically discussed in part I of this study. In this work, HF-LLLME with osmosis was coupled with high performance liquid chromatography–triple quadrupole mass spectrometry (HPLC–triple quadrupole MS/MS) to analyze eight gibberellins (gibberellin A1, gibberellin A3, gibberellin A4, gibberellin A7, gibberellin A8, gibberellin A9, gibberellin A19 and gibberellin A20) in rice plant samples. According to the theory of HF-LLLME with osmosis, single factor experiments, orthogonal design experiments and mass transfer simulation of extraction process were carried out to select the optimal conditions. Cyclohexanol – n-octanol (1:3, v/v) was selected as organic membrane. Donor phase of 12mL was adjusted to pH 2 and 20% NaCl (w/v) was added. Acceptor phase with an initial volume of 20μL was the solution of 0.12molL−1 Na2CO3–NaHCO3 buffer (pH 9). Temperature was chosen to be 30°C and extraction time was selected to be 90min. Under optimized conditions, this method provided good linearity (r, 0.99552–0.99991) and low limits of detection (0.0016–0.061ngmL−1). Finally, this method was applied to the analysis of endogenous gibberellins from plant extract which was obtained with traditional solvent extraction of rice plant tissues, and the relative recoveries were from 62% to 166%.

Ultrahigh performance liquid chromatography–triple quadrupole mass spectrometry inhibitors fishing assay: A novel method for simultaneously screening of xanthine oxidase inhibitor and superoxide anion scavenger in a single analysis

Xanthine oxidase (XOD) inhibitors and superoxide anion scavengers play an important role in the treatment of gout and the inhibition of many diseases related to superoxide anion. The respective quantitation of uric acid and superoxide anion by traditional spectroscopic methods is routine in XOD inhibitors and superoxide anion scavengers screening at laboratories worldwide. In the present study, we established an ultrahigh performance liquid chromatography and triple quadrupole mass spectrometry (UHPLC–TQ-MS) method of higher accuracy and speed that combines screening of superoxide anion scavenger and XOD inhibitor in a single analysis by adding WST-1 (2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium sodium salt) to the enzymatic reaction. We applied the established method to determine the XOD inhibitory activities and superoxide scavenging activities of some herbal extracts and compounds from natural products, which could be classified into six groups based on the results of the assay. Our innovative protocol is fast, accurate and robust. Moreover, it can eliminate false positive and false negative results which may occur in the traditional spectroscopic methods.

Rapid Determination of Anisatin in Biological Sample by Ultra Performance Liquid Chromatography-Triple Quadrupole Mass Spectrometry

A rapid UPLC-MS/MS method was developed for the quantitative determination of anisatin, as a marker of the sesquiterpene lactones in various Illicium species, in plasma, urine, vomit, and plant samples using a triple quadrupolep mass spectrometer. The proposed assay includes multi-function impurity adsorption SPE cleanup procedure for plasma sample, diatomite solid supported liquid/liquid extraction for urine, and tert-butyl methyl ether liquid/liquid extraction for plant sample. The satisfactory recoveries were obtained. Chromatographic separation was performed on an UPLC BEH C-18 column (50 mm x 2. 1 mm x 1. 7 mu m) using gradient elution with water-methanol, and detected by the negative electrospray ionization-MS/MS method under multiple reaction monitor mode. The cycle time of each analysis was 5. 0 min. The average recoveries were 92. 6% - 100. 3% and 101% - 118% with RSDs of 3. 8% - 11% and 6. 4% - 17% (n=6) for anisatin in plasma and urine, respectively. The limits of quantitation (S/N=10) were 2 mu g/L and 1 mu g/L for plasma and urine sample, respectively. The method is simple, selective and sensitive to the determination of anisatin in biological sample for toxicological purposes.

Analysis of hydroxylated polybrominated diphenyl ethers in plant samples using ultra performance liquid chromatography-mass spectrometry

A method was developed for the analysis of hydroxylated brominated diphenyl ethers (OH-PBDEs) in plant samples using an ultra performance liquid chromatography-triple quadrupole mass spectrometer (UPLC-ESI-MS/MS) in negative mode. Plant samples were extracted and cleaned up through florisil column, resolved on a 100 mm C18 column with linear gradient elution and detected by mass spectrometry in multiple reaction monitoring (MRM) mode. The method provided good recoveries ranging from 68.2% to 94.6%, relative standard deviation (RSD) in the range of 3.2%–9.1%, and limits of quantification (LOQ) defined as the signal-to-noise ratio of 10 of 0.3–2.1 ng/g. It allowed a fast separation and sensitive quantification of the isomers and homologues of seven OH-PBDE congeners 2′-OH-BDE-3, 3′-OH-BDE-7, 4′-OH-BDE-17, 3′-OH-BDE-28, 3-OH-BDE-47, 5-OH-BDE-47 and 6-OH-BDE-47. The method was successfully applied to identify and quantify the formation of hydroxylated metabolites in alfalfa exposed to BDE-209. Five OH-PBDEs were detected in plant tissues, and more congeners were found in roots than in shoots. To our knowledge, this work represents the first attempt to validate UPLC-MS/MS method to quantify OH-PBDEs in plant samples without derivatization.

Reprint of: Removal and formation of chlorinated triclosan derivatives in wastewater treatment plants using chlorine and UV disinfection

Triclosan, a common antimicrobial agent, may react during the disinfection of wastewater with free chlorine to form three chlorinated triclosan derivatives (CTDs). This is of concern because the CTDs may be photochemically transformed to tri- and tetra-chlorinated dibenzo- p-dioxins when discharged into natural waters. In this study, wastewater influent, secondary (pre-disinfection) effluent, and final (post-disinfection) effluent samples were collected on two occasions each from two activated sludge wastewater treatment plants, one using chlorine disinfection and one using UV disinfection. Concentrations of triclosan and three CTDs were determined using ultra performance liquid chromatography–triple quadrupole mass spectrometry with isotope dilution methodology. Triclosan and the CTDs were detected in every influent sample at levels ranging from 453 to 4530 and 2 to 98 ng L −1, respectively, though both were efficiently removed from the liquid phase during activated sludge treatment. Triclosan concentrations in the pre-disinfection effluent ranged from 36 to 212 ng L −1, while CTD concentrations were below the limit of quantification (1 ng L −1) for most samples. In the treatment plant that used chlorine disinfection, triclosan concentrations decreased while CTDs were formed during chlorination, as evidenced by CTD levels as high as 22 ng L −1 in the final effluent. No CTDs were detected in the final effluent of the treatment plant that used UV disinfection. The total CTD concentration in the final effluent of the chlorinating treatment plant reached nearly one third of the triclosan concentration, demonstrating that the chlorine disinfection step played a substantial role in the fate of triclosan in this system.

Removal and formation of chlorinated triclosan derivatives in wastewater treatment plants using chlorine and UV disinfection

Triclosan, a common antimicrobial agent, may react during the disinfection of wastewater with free chlorine to form three chlorinated triclosan derivatives (CTDs). This is of concern because the CTDs may be photochemically transformed to tri- and tetra-chlorinated dibenzo- p-dioxins when discharged into natural waters. In this study, wastewater influent, secondary (pre-disinfection) effluent, and final (post-disinfection) effluent samples were collected on two occasions each from two activated sludge wastewater treatment plants, one using chlorine disinfection and one using UV disinfection. Concentrations of triclosan and three CTDs were determined using ultra performance liquid chromatography–triple quadrupole mass spectrometry with isotope dilution methodology. Triclosan and the CTDs were detected in every influent sample at levels ranging from 453 to 4530 and 2 to 98 ng L −1, respectively, though both were efficiently removed from the liquid phase during activated sludge treatment. Triclosan concentrations in the pre-disinfection effluent ranged from 36 to 212 ng L −1, while CTD concentrations were below the limit of quantification (1 ng L −1) for most samples. In the treatment plant that used chlorine disinfection, triclosan concentrations decreased while CTDs were formed during chlorination, as evidenced by CTD levels as high as 22 ng L −1 in the final effluent. No CTDs were detected in the final effluent of the treatment plant that used UV disinfection. The total CTD concentration in the final effluent of the chlorinating treatment plant reached nearly one third of the triclosan concentration, demonstrating that the chlorine disinfection step played a substantial role in the fate of triclosan in this system.

A novel and specific method for the determination of aristolochic acid-derived DNA adducts in exfoliated urothelial cells by using ultra performance liquid chromatography–triple quadrupole mass spectrometry

Aristolochic acid nephropathy (AAN) is associated with the prolonged exposure to nephrotoxic and carcinogenic aristolochic acids (AAs). DNA adducts induced by AAs have been proven to be critical biomarkers for AAN. Therefore, accurate and specific quantification of AA–DNA adducts is important. In this study, a specific method using ultra performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) was developed and applied for the determination of 7-(deoxyadenosin-N6-yl)aristolactam I (dA-AAI) in exfoliated urothelial cells of AA-dosed rats. After the isolation from urine samples, DNA in urothelial cells were subjected to enzymatic digestion and solid-phase extraction on a C18 Sep-Pak cartridge for the enrichment of DNA adducts. The sample extracts were analyzed by reverse-phase UPLC–MS/MS with electrospray ionization in positive ion mode. The quantification of the AA–DNA adduct was performed by using multiple reaction monitoring with reserpine as internal standard. The method provided good accuracy and precision with a detection limit of 1ng/ml, which allowed the detection of trace of dA-AAI in exfoliated urothelial cells. After one-month oral dose of AAI at 10mg/kg/day, 2.1±0.3 dA-AAI per 109 normal dA was detected in exfoliated urothelial cells of rats. Compared to the traditional methods such as 32P-postlabelling and HPLC with fluorescence detection, the developed UPLC–MS/MS method is more specific and rapid with a retention time of 4min. The outcome of this study may have clinical significance for diagnosing and monitoring AA-associated disease because detection of DNA adducts in exfoliated urothelial cells is non-invasive and convenient.

Dioxin Photoproducts of Triclosan and Its Chlorinated Derivatives in Sediment Cores

Triclosan, a widely used antimicrobial, is known to undergo phototransformation in aqueous solution to form 2,8-dichlorodibenzo-p-dioxin (2,8-DCDD). Two sediment cores from a wastewater-impacted depositional zone of the Mississippi River were analyzed for triclosan by ultra performance liquid chromatography-triple quadrupole mass spectrometry (UPLC-MS-Q(3)) and for a suite of polychlorinated dioxins and furans by high resolution gas chromatography-mass spectrometry (HRGC-MS) to provide evidence of this photoreaction in the environment. 2,8-DCDD was detected at levels that trended with the historical use of triclosan since its introduction in the 1960s. Three other dioxin congeners, 2,3,7-TCDD, 1,2,8-TriCDD, and 1,2,3,8-TCDD, which are known photoproducts of chlorinated derivatives of triclosan, were also detected with similar trend profiles. These four congeners comprised the majority of di- through tetra-chlorinated dioxins. The trend profile of these specific dioxin congeners did not correlate with the trend profile of the higher-chlorinated dioxin homologues or any chlorinated furan homologues, suggesting a unique source. These results are fully consistent with the phototransformation of triclosan and its chlorinated derivatives that form during wastewater chlorine disinfection as the source of 2,8-DCDD, 2,3,7-TriCDD, 1,2,8-TriCDD, and 1,2,3,8-TCDD in this aquatic environment. As the levels of triclosan-derived dioxins increased over time and the total level of chlorinated dioxins decreased, the contribution of triclosan-derived dioxins to the total dioxin pool increased to as high as 31% by mass in recent years, indicating that their contribution to total dioxin toxicity may need consideration.