Determination of perfluorooctane sulfonic acid in cosmetics by high-perfor⁃ mance liquid chromatography-tandem mass spectrometryEI北大核心CSCD

A high performance liquid chromatography-tandem mass spectrometry（HPLC-MS/MS）method was developed for the determination of perfluorooctane sulfonic acid （PFOS）in cosmetics. The cosmetic samples were extracted with methanol by ultrasonication,and PFOS was quantified by HPLC-MS/MS. The samples were detected in negative multiple reaction monitoring（MRM）mode using an Agilent Poroshell 120 EC-C18 （100 mm× 2.1 mm,2.7 µμm）column with a gradient elution using 0.1% formic acid aqueous solution（A）-methanol（B）as the mobile phase. The results showed that the linearity of PFOS was good in the range of 1-100 µμg/L with the correlation coefficient r2 larger than 0.9998;the limits of detection and limits of quantification were 0.015 and 0.050 mg/kg,respectively. The average recoveries were 98.7%-112.5%,and the relative standard deviations （RSDs）were less than 5%. The method is suitable for the determination of PFOS in cosmetics. © 2023, Youke Publishing Co.,Ltd. All rights reserved.     

Determination of synthetic musk in ground water by liquid-liquid extraction-gas chromatography mass spectrometryEI北大核心CSCD

A gas chromatography-mass spectrometry GC-MS method was established to determine three different synthetic musksSMsfrom ground water. Dichloromethane as the extracting solventthe concentrated extracts were tested by GC-MS using the external standard quantitative method. Each sample was extracted three times with 40 mL dichloromethane respectively. The linearity test was carried out in the range of 20.0 to 2000 μµg/L the relative standard deviationRSDRRFof average relative response factor was less than 8.7%and the limits of detectionLODswere in the range of 0.007 to 0.012 μµg/L. The recoveries of three spiked ground water samples were all between 98.1% and 117.0%and the relative standard deviations were less than 13%. Musk xylene in the ground water sample was 0.013 μµg/Land the spiked real sample had the recoveries higher than 80%. This method was suitable for the detection of trace SMs in ground water. © 2022, Youke Publishing Co.,Ltd. All rights reserved.     

Determination of the migration of fourteen endocrine disruptors in food packaging materials by liquid chromatography-tandem mass spectrometryEI北大核心CSCD

A method for the determination of the migration of 14 endocrine disruptors（bisphenol A,bisphenol E,bisphenol F,bisphenol S,bisphenol B,bisphenol Z,bisphenol AF,bisphenol AP,tetrabromobisphenol A, tetrachlorobisphenol A,octylphenol,4-n-octylphenol,4-nonylphenol and 4-n-nonylphenol）in food packaging materials by liquid chromatography-tandem mass spectrometry was developed. The samples were soaked in water,4% acetic acid solution,10% ethanol solution,50% ethanol solution,olive oil,simulated sweat and simulated saliva. The soakings were purified by solvent extraction or Oasis HLB solid phase extraction. After separation by a Waters Atlantis™ T3 column,the samples were determined by multiple reaction monitoring mode with electrospray negative ion source,and quantified by matrix external standard method. The linear correlation coefficients of 14 endocrine disruptors were 0.9901-0.9986,the recoveries were 82.3%-108.7% with the relative standard deviations of 0.8%-6.8%,the limits of detection were 0.1-0.5 μµg/L and the limits of quantification were 0.3-1.5 μµg/L. © 2023, Youke Publishing Co.,Ltd. All rights reserved.     

A modified QuEChERS-gas chromatography-mass spectrometry method for the determination of pesticide residues in Lonicera japonicae FlosEI北大核心CSCD

A modified QuEChERS-gas chromatography-mass spectrometry method using multi-walled carbon nanotubes （MWCNTs）as adsorbent was established for the determination of 72 pesticide residues in Lonicera japonicae Flos. The sample was extracted with Association of Official Agricultural Chemists （AOAC）extracting package，purified with MWCNTs-modified purification tube，analyzed with dynamic multiple reaction monitoring mode，and quantified with external standard method of matrix-matched standard curve. The 72 pesticides showed good linearities in the corresponding concentration ranges with correlation coefficients greater than 0.9936. The limits of detection were 0.001-0.178 μµg/kg，and the limits of quantitation were 0.002-0.593 μµg/kg. The average recoveries for four spiked levels ranged from 60.1% to 118.0%，with the relative standard deviations of 2.2%-17%. © 2023, Youke Publishing Co.,Ltd. All rights reserved.     

Determination of macrolides in livestock excreta by syringe purification coupled with liquid chromatography tandem mass spectrometryEI北大核心CSCD

A method of syringe-dispersive solid-phase extraction combined with ultrahigh performance liquid chromatography with tandem mass spectrometry for the simultanous determination of 10 macrolides in manurebased fertilizers was developed. After extraction with methanol and acetonitrile,the extracts were purified by insyringe dispersion solid-phase extraction in syringes pre-filled with 60 mg PSA and 30 mg C18. The resulted extracts were further separated by a BEH C18 column,detected by multiple reaction monitoring in electrospray positive ion mode,and quantified by matrix-matched external standard method. The results showed that the recoveries of the target compounds ranged from 70% to 110% at three spiked levels（10,30,and 50 μµg/kg）with the relative standard deviations ranged from 1.4% to 12%. The limits of detection and quantification were 0.57 1.75 and 2.77-5.40 μµg/kg,respectively. This method was suitable for the simultaneous determination of residual macrolides in organic fertilizers. © 2023, Youke Publishing Co.,Ltd. All rights reserved.     

Determination of insulin aspart in plasma by liquid chromatography-quadrupole electrostatic field orbitrap high-resolution mass spectrometryEI北大核心CSCD

A rapid detection method for insulin aspart in human plasma was established by using liquid chromatography-quadrupole electrostatic field orbitrap high-resolution mass spectrometry. Samples were pretreated with a precipitant of methanol-acetonitrile-acetic acid solution (49:49:2, V/V/V), an Agilent Eclipse Plus C18 column (50 mm×2.1 mm, 3.5 µm) was selected, with 0.1% aqueous formic acid and 0.1% formic acid[1]acetonitrile as mobile phases for gradient elution, and mass spectrometry was performed in selected ions monitoring (SIM) scan mode. The experimental results showed that the linear relationship of insulin aspart in human plasma was good in the range of 0.1-10 µg/mL (R2=0.9938), with the limit of quantification of 0.1 µg/mL, and the limit of detection of 0.05 µg/mL. The recoveries ranged from 71.6% to 106.2%, and the relative standard deviations (RSDs) of the intra-day and inter-day were both less than 15%. The method can meet the inspection needs of actual cases. © 2023, Youke Publishing Co.,Ltd. All rights reserved.     

Three-element doped carbon dots for the detection of p-nitrophenolEI北大核心CSCD

Based on the characteristics that heteroatom doping can improve the luminescence performance of carbon dotsa new type of three-element co-doped carbon dots NSSi-CDswas prepared. The synthesis conditions were optimizedand the morphologystructure and luminescence properties of NSSi-CDs were characterized. NSSi-CDs can emit 450 nm blue fluorescence under excitation at 370 nmand the fluorescence quantum yield reached 11%. The study found that p-nitrophenol PNPhas a strong fluorescence quenching effect on NSSi-CDsand thus a new method for the determination of PNP with NSSi-CDs fluorescent probe was constructed. When the concentration of PNP was in the range of 0.9-60 μµmol/Lit had a good linear relationship with the fluorescence quenching efficiencyF0 /Fand the detection limit was 0.36 μµmol/L. This method was used to determine PNP in actual water samples with good recoveries of 90.6%-95.2%. © 2022, Youke Publishing Co.,Ltd. All rights reserved.     

Low temperature purification method for the determination of abamectin and ivermectin in edible oils by liquid chromatographytandem mass spectrometry

In this study,a method based on low temperature purification(LTP) coupled with liquid chromatography-tandem mass spectrometry(LC-MS/MS) was developed for the determination of abamectin(ABA) and ivermectin(IVR) in edible oils.ABA and IVR were extracted using conventional liquid-liquid extraction followed by purification via precipitation of interfering fatty components at low temperature without an additional cleanup step.LTP is simple,easy to use,labour-saving and cost effective,and requires reduced amounts of organic solvent.The linear ranges of ABA and IVR were 5-1000 μg/L using matrix-matched standards.Limits of detection(LOD) and limits of quantification(LOQ)were in the range of 0.1-0.4 μg/kg and 0.3-1.3 μg/kg,respectively.The LOQs were below the strictest maximum residue limits established by Codex Alimentarius Commission.Recoveries at three spiked levels of 10,20 and 100 μg/kg in peanut oil,corn oil,olive oil,soybean oil and lard ranged from 71.1%to119.3%with relative standard deviations of 3.2%-10.3%,which were in agreement with those obtained by the solid phase extraction method.The proposed method was utilized in the analysis of 10 edible oil samples from local market and neither ABA nor IVR was detected.As far as we know,this is the first time that LTP is applied to the determination of avermectins in edible oils.     

Analysis of nitrobenzene compounds in water and soil samples by graphene composite-based solid-phase microextraction coupled with gas chromatography–mass spectrometry

In this work, solid-phase microextraction coupled with gas chromatography–mass spectrometry was developed to determine trace levels of nitrobenzene compounds in water and soil samples. Graphene was chosen as the extraction material and its composite was coated on a stainless steel wire through sol–gel technique for the solid phase microextraction. The key parameters influencing the extraction efficiency were optimized. Under the optimal conditions, the linearity for the compounds was observed in the range of 0.02–15.0 mg/L for water samples, and 0.2–60.0 mg/kg for soil samples, with the correlation coefficients（r） of 0.9966–0.9987. The limits of detection of the method were 0.0025–0.005 mg/L for water samples, and 0.02–0.04 mg/kg for soil samples. The recoveries for the spiked samples were in the range of 72.0%–113.2%, and the precision, expressed as the relative standard deviations, was less than 12.1%.     

Simultaneous determination of eleven amphenicols and antiviral drugs in aquatic products by ultra-high performance liquid chromatography-tandem mass spectrometry coupled with PRIME HLB solid phase extractionEI北大核心CSCD

An efficient ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was established for the simultaneous determination of 11 amphenicols and antiviral drugs in aquatic products including fish, shrimp, soft-shell turtle and shellfish samples. Each sample was dispersed with 4%(w/w)sodium chloride solution, and extracted with 2%(V/V) ammonia-ethyl acetate solution. After the concentration of the extract, the residue was redissolved in 0.2%(V/V) aqueous solution of formic acid-acetonitrile (20∶80, V∶V), purified with Oasis PRIME HLB cartridge, and detected by UPLC-MS/MS. The samples were analyzed directly on the ZORBAX RRHD Eclipse Plus C18 column using 5 mmol/L ammonium formate and acetonitrile as mobile phase. The quantitative determination of the analytes was carried out under the multiple reaction monitoring mode with positive and negative electrospray ionization using internal standard method. Results showed that there were good linear relationships for all analytes in the corresponding concentration ranges, with the correlation coefficients not less than 0.996. The limits of quantification ranged from 0.2 to 2.0 µg/kg. The average spiked recoveries were between 84.6% and 110% with the relative standard deviations of 1.0% to 14%. The method, which has been used in risk monitoring, is suitable for rapid determination of amphenicols and antiviral drugs in aquatic products. © 2023, Youke Publishing Co.,Ltd. All rights reserved.     

Determination of 15 polycyclic aromatic hydrocarbons in lotus root by QuEChERS-high performance liquid chromatographyEI北大核心CSCD

A method for the determination of 15 priority polycyclic aromatic hydrocarbonsPAHsin lotus root by QuEChERS technique combined with high performance liquid chromatography HPLC was established. Lotus root samples were extracted by acetonitrilefiltrated after salting out and purified by C18 and primary secondary aminePSAsorbent. Then the 15 kinds of PAHs were analyzed by HPLC with diode array detector or fluorescence detector after being separated by Athena PAHs column. When the 15 kinds of PAHs were analyzed by diode array detectorthe linear relationships were good between 0.02 and 1.0 mg/L with the correlation coefficients above 0.99 for all the 15 kinds of PAHs. The limits of quantitation were 0.02 mg/kg for allthe average recoveries of the 15 kinds of PAHs were 84.7%-117.1%and the relative standard deviations were 0.73%-11%. When the 14 kinds of PAHsexcept for acenaphthyleneanalyzed by fluorescence detectorthe linear relationships were good between 0.001 and 1.0 mg/L with the correlation coefficients above 0.99 for all the 14 kinds of PAHs except for acenaphthylene. The limits of quantitation were 5 μµg/kg for allthe average recoveries of the 14 kinds of PAHsexcept for acenaphthylenewere 69.1%-111.8%and the relative standard deviations were 0.18%-9.7%. Diode array detector and fluorescence detector are complementary. Diode array detector can analyze all the PAHsbut its sensitivity is relatively low. Fluorescence detector is not suitable for acenaphthylene with weak fluorescence signalbut its sensitivity is much higher than that of diode array detector. This method is suitable for simultaneously and quickly determination of 15 kinds of PAHs in lotus root. © 2022, Youke Publishing Co.,Ltd. All rights reserved.     

Determination of 12 additives in beverages by evaporation-assisted dispersive liquid-liquid microextraction based on the solidification of floating organic droplets combined with liquid chromatographyEI北大核心CSCD

An analytical method for the simultaneous determination of 12 additives in beverages was developed using evaporation-assisted dispersive liquid-liquid microextraction based on the solidification of floating organic droplets EVA-DLLME-SFOcombined with high performance liquid chromatography HPLC. The samples were extracted twice with 70%V/Vmethanol aqueous solution and extracted by EVA-DLLME-SFO method after the combination of the extractsand finally determined by HPLC. Extraction parameterssuch as types and amounts of extractantevaporant and heating agentthe concentration of saltand the extraction time were optimized. Under the optimized conditionsthere were good relationships in the ange of 0.25-50 μµg/mL with the limits of detection of 1.5 to 13.6 mg/kg and limits of quantification of 5.2 to 45.3 mg/kg. The recoveries at three spiked levels1025 and 50 mg/kgwere 76.8% to 101.2% with the relative standard deviations of 0.11% to 4.7%. The method can be used for rapid detection of 12 additives in beverages. © 2022, Youke Publishing Co.,Ltd. All rights reserved.     

Sensitive determination of fenpropathrin, cyhalothrin and deltamethrin in environmental water samples using multiwalled carbon nanotubes cartridge prior to HPLC

This paper described a new method for the trace determination of fenpropathrin, cyhalothrin and deltamethrin using multiwalled carbon nanotubes （MWCNTs） cartridge. Important parameters, such as the sample pH, eluent and its volume, sample flow rate and sample volume were investigated in detail. The linear ranges, the detection limits, and precisions （R.S.D.） were in the range of 0.1- 40 μg L^-11, 1.34.3 ng L^-1 and 2.3-2.8%, respectively. The performance of the proposed method was validated with real water samples, and the spiked recoveries were in the range of 91.7-117.8%, respectively. The experimental results demonstrated that the proposed method was an excellent alternative for the routine analysis of such pollutants in environmental samples. 2007 Qing Xiang Zhou. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.     

Sulphonamide Residues in Italian Surface and Drinking Waters: A Small Scale Reconnaissance

The occurrence of antibiotics in the aquatic environment is an important emerging issue due to potential adverse effect of these compounds on ecosystem and human health. For a correct environmental risk assessment there is a need for appropriate analytical methods for monitoring antibiotic residues in a variety of water matrices. This paper describes a method for the determination of eleven sulphonamide compounds in surface and drinking waters using solid-phase extraction and liquid chromatography-tandem mass spectrometry. Recoveries of the analytes in both surface and drinking water matrices at different fortification levels, always exceed 87%; the limits of quantification in surface water samples are between 0.005 and 0.021 μg L⁻¹ depending on the compound, and the interday method precision is less than 12%. Matrix effects were evaluated in drinking and surface water samples. The method has been applied to a small scale reconnaissance of river, lake, mineral and municipal water samples; results indicate the occurrence of sulphonamides in some surface and mineral waters analyzed.     

Determination of the impurity of isopentylamine hydrochloride in the intermediate of bortezomib by HPLC with pre-column derivatizationEI北大核心CSCD

A method was developed for the simultaneous determination of R-pinacol-1-amino-3-methylbutylborate hydrochloride and isopentylamine hydrochloride by pre-column derivatization high performance liquid chromatography HPLC with dichloromethane as solventtriethylamine as acid binding agent and benzoyl chloride as derivative reagent. R-pinacol-1-amino-3-methylbutylborate hydrochloride and isopentylamine hydrochloride reacted with derivatization reagent in an ice bath for 10 min. The derivatives were qualitatively determined by HPLC-mass spectrometryHPLC-MS. HPLC was performed on an AgelaVenusil MP C18 2column using methanol-water 7030V/Vas mobile phase. The flow rate was 1.0 mL/minthe detection wavelength was 236 nm and the column temperature was 35 . The UV absorption produced after derivatizationwhich could be detected by HPLC with good specificity. Isopentylamine hydrochloride derivative showed an excellent linearity in the range of 0.075-30 μµg/mLwith the limit of quantification and the limit of detectionLODof 0.075 and 0.030 μµg/mLrespectively. And the S/N of the LOQ and the LOD were 44.6 and 7.8respectively. The average recoveries were 97.7%-104.0% with the RSD of 2.9%. The method is suitable for the determination of isoamylamine hydrochloride and has significant reference value for the determination of other amine salt without UV absorption. © 2022, Youke Publishing Co.,Ltd. All rights reserved.     

Capillary Electrophoresis for the Simultaneous Determination of Metals by Using Ethylenediamine Tetraacetic Acid as Complexing Agent and Vancomycin as Complex Selector

A new separation system of capillary electrophoresis for the simultaneous determination of metals by using ethylenediamine tetraacetic acid （EDTA） as complexing agent and employing vancomycin as complex selector was described. The Z-shape cell capillary electrophoresis was used to enhance the sensitivity for the determination of the complexes of Cu（Ⅱ）, Ni（Ⅱ）, Co（Ⅱ） and Fe（Ⅲ） with EDTA. The partial filling method （co-current mode） was used in order to increase the selectivity of the electrophoretic method, meanwhile vancomycin was not present at the detector path during the detection of metal-EDTA complexes. The vancomycin concentration, phosphate concentration and pH of the buffer strongly influenced mobility, resolution and selectivity of the studied analytes. Under the optimal condition, the relative standard deviations （n=5） of the migration time and the peak area were less than 3.14% and 7.35%, respectively. Application of the Z-shape cell capillary electrophoresis method with UV detection and vancomycin loading led to the reliable determination of these metal ions in tap water and the recoveries were 97%-101%. The detection limits based on a signal to noise ratio of 3 ： 1 were found in the range of 2-10 μg·L^-1.     

Determination of sulfite in water samples by flow injection analysis with fluorescence detection

<正>A fast,sensitive,and reliable method for the determination of sulfite(SO_3~(2-)) in fresh water and seawater samples was developed.The proposed method was based on the reaction of o-phthalaldehyde(OPA)-sulfite-NH_3 in alkaline solution,with flow injection analysis and fluorescence detection.The experimental parameters were investigated in pure water and seawater matrixes. The detection limits(S/N = 3) were 0.006μmol/L in pure water and 0.018μmol/L in seawater for SO_3~(2-).The method was successfully applied to analyze SO_3~(2-) in the samples of rain water and flue gas desulfurization seawater.     

High performance liquid chromatography analysis of p-aminophenol synthesized by nitrobenzene transfer hydrogenation using formic acid as hydrogen sourceEI北大核心CSCD

Qualitative analysis of the main by-product of 4-hydroxybenzamide in the synthesis of p-aminophenol bynitrobenzene transfer hydrogenation with formic acid as hydrogen source was carried out by electrospray ionization mass spectrometry. The reaction system was quantitatively analyzed by high performance liquid chromatography. The chromatographic conditions were shown as followsShim pack VP-ODS column250 mm× 4.6 mm5 μµmdetection wavelength of 254 nmVmethanolVbuffer solution=114.8 mmol/L sodium dihydrogen phosphate solution1.9 mmol/L dibasic sodium phosphate solutionas the mobile phase and the flow rate of 0.8 mL/min with a column temperature of 35. Nitrobenzenep-aminophenolaniline and formylaniline in the reaction system were quantitatively analyzed by standard curve method with methyl N-phenylcarbamate as internal standard. The correlation coefficientsR2were 0.99930.99950.9998 and 0.9992 for these analytes respectively. The relative standard deviations RSDs were less than 1.0% 0.3% 0.2% and 0.4% respectively. The recoveries were in the ranges of 95.5%-102.6%101.2%-104.8%95.1%-99.8% and 95.7%-101.1%respectively. This method can be used for the simultaneous determination of main and by-products in the transfer hydrogenation of nitrobenzene with formic acid as hydrogen source. © 2022, Youke Publishing Co.,Ltd. All rights reserved.     

Determination of captopril in pharmaceutical preparation and biological fluids using two- and three-way chemometrics methods

Spectrophotometric method has been developed for the direct quantitative determination of captopril in pharmaceuticalpreparation and biological fluids(human plasma and urine)samples.The method was accomplished based on parallel factoranalysis(PARAFAC)and partial least squares(PLS).The study was carried out in the pH range from 2.0 to 12.8 and with aconcentration from 0.70 to 61.50 μg mL~(-1)of captopril.Multivariate calibration models such as PLS at various pH and PARAFACwere elaborated from ultraviolet spectra deconvolution and captopril determination.The best models for this system were obtainedwith PARAFAC and PLS at pH 2.0.The applications of the method for determination of real samples were evaluated by analysis ofcaptopril in pharmaceutical preparations and biological fluids with satisfactory results.The accuracy of the method,evaluatedthrough the RMSEP,was 0.5801 for captopril with best calibration curve by PARAFAC and 0.6168 for captopril with PLS at pH 2.0model.