RESUMEN
A rapid,accurate,and sensitive analytical method,ultrasonication-assisted spraying based fine droplet formation-liquid phase microextraction-gas chromatography-mass spectrometry (UA-SFDF-LPME-GC-MS),was proposed for the determination of trace amounts of hydroxychloroquine sulfate in human serum,urine,and saliva samples.To determine the best extraction strategy,several liquid and solid phase extraction methods were investigated for their efficiencies in isolation and preconcentration of hydroxychloroquine sulfate from biological matrices.The UA-SFDF-LPME method was determined to be the best extraction method as it was operationally simple and provided accurate results.Variables such as the extraction solvent,spraying number,sodium hydroxide concentration and volume,sample vol-ume,mixing method,and mixing period were optimized for the proposed method using the one-variable-at-a-time approach.In addition,Tukey's method based on a post hoc comparison test was employed to evaluate the significant difference between the parameters inspected.After the optimiza-tion studies,the limit of detection (LOD) and limit of quantification (LOQ) were determined to be 0.7 and 2.4 μg/kg,respectively.The sensitivity of the GC-MS system based on the LOD was enhanced approxi-mately 440-fold when the UA-SFDF-LPME method was employed.Spiking experiments were also con-ducted for the human serum,urine,and saliva samples to determine the applicability and accuracy of the proposed method.Recoveries for the human serum,urine,and saliva samples were found to be in the ranges of 93.9％-101.7％,95.2％-105.0％,and 93.1％-102.3％,respectively.These results were satisfactory and indicated that the hydroxychloroquine sulfate level in the above biological samples could be analyzed using the proposed method.
RESUMEN
Enrichment of trace bioactive constituents and metabolites from complex biological samples is chal-lenging. This study presented a one-pot synthesis of magnetic polydopamine nanoparticles (Fe3O4@-SiO2@PDA NPs) with multiple recognition sites for the magnetic dispersive solid-phase extraction (MDSPE) of ginsenosides from rat plasma treated with white ginseng. The extracted ginsenosides were characterized by combining an ultra-high-performance liquid chromatography coupled to a high-resolution mass spectrometry with supplemental UNIFI libraries. Response surface methodology was statistically used to optimize the extraction procedure of the ginsenosides. The reusability of Fe3O4@-SiO2@PDA NPs was also examined and the results showed that the recovery rate exceeded 80％ after recycling 6 times. Furthermore, the proposed method showed greater enrichment efficiency and could rapidly determine and characterize 23 ginsenoside prototypes and metabolites from plasma. In com-parison, conventional methanol method can only detect 8 ginsenosides from the same plasma samples. The proposed approach can provide methodological reference for the trace determination and charac-terization of different bioactive ingredients and metabolites of traditional Chinese medicines and food.
RESUMEN
Objective@#To establish a method for determination the S-phenylmercapturic acid in urine by dispersive solid-phase extraction using Humic Acid/Fe3O4 magnetic nanocomposite as adsorbent.@*Methods@#The 5 ml of urine samples were adjusted to pH 1.0 and extracted by Fe3O4@HA. Then the analytes were separated on EC-C18 capillary column and detected by HPLC-VWD. The S-phenylmercapturic acid was characterized by the retention time and quantified by peak area and external standard method.@*Results@#The standard curves of SPMA showed significant linearity between 0.04~1.00 mg/L (r=0.999 7) . The average recovery was 94.2%~102.4%. The intra-day and inter-day precisions (RSD) were 2.9~6.7% (n=6) and 3.1~7.5% (n=6) respectively. The detect limit of SPMA was 0.012 g/L (S/N=3) .@*Conclusion@#This method is simple, rapid, sensitive and accurate. It is applicable for determination of SPMA in the urine of works who were exposed to benzene.
RESUMEN
An efficient method for the analysis of multiclass plant growth regulators and pesticide (imidacloprid, acetamiprid) residues in tea was developed based on ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The samples were extracted with acetonitrile/formic acid (99∶1, V/V) solution, cleaned up with four sorbents including C18, strong anion exchanger (SAX), primary secondary amine (PSA) and anhydrous MgSO4. The compounds were separated on a HSS T3 column under positive/negative electrospray ionization mode, detected by scheduled multiple reaction monitoring (SMRM), and quantified by matrix-matched external standard curves. All pesticide residues showed good linearity in the concentration range of 1-200 μg/L (6-benzylaminopurine, paclobutrazol, uniconazole, forchlorfenuron, mepiquat chloride, imidacloprid, acetamiprid) or 5-1000 μg/L (2,4-dichlor-ophenoxyacetic acid, 4-chlorophenoxyacetic acid, indole-3-acetic acid, gibberellic acid, 1-naphthaleneacetic acid, indole-3-butyric acid) , with correlation coefficient (R2≥0.99). Limits of detection (LOD, S/N=3) and limits of quantitation (LOQ, S/N=10) were 0.18-9.68 μg/kg and 0.61-32.26 μg/kg, respectively. In addition, the spiked recoveries of tea samples were 73.1％-108.9％, and RSDs were 0.6％-8.0％. This method was applied to commercial samples, and all the detections were confirmed by acquiring transitions for each pesticide in the samples.
RESUMEN
Objective In order to analyze of poisoning causes,a new method was established utilizing hydrophilic liquid chromatography-tandem triple quadrupole mass spectrometer (HILIC-MS/MS) coupled with dispersive solid phase extraction for rapid qualitative and quantitative analysis of tetrodotoxin in nassarius and shellfish.Methods Sample (1.0 g) was extracted with 0.1％ acetic acid in boiling water bath,purified by dispersive solid phase extraction with 50 mg hydrophilic-lipophilic balance (HLB),5 mg graphitized carbon black (GCB) and protein precipitation with acetonitrile,and then filtered through a polytetrafluoroethylene (PTFE) membrane.The analytes were separated on a HILIC column,and detected in selected reaction monitoring (SRM) mode via positive electrospray ionization.The matrix matching and external standard method was used for quantification.Results Tetrodotoxin showed good linearity in the concentration range between 2.0 and 40.0 ng/ml,the correlation coefficient was higher than 0.999.The detection limit of tetrodotoxin in seafood was 10.0 pg/kg.The rates of recovery varied between 74.2％ and 87.9％ with relative standard deviations from 2.3％ to 9.1％ at spiked concentrations of 25,100 and 200 pg/kg.The proposed method was applied in the detection of tetrodotoxin in shellfish and nassarius from coastal cities of Zhejiang Province.Conclusion The method was accurate,fast,easy to operate,which could meet the requirements of public health emergency testing or routine testing.
RESUMEN
A method of metal organic nanotubes-based dispersive solid phase extraction-gas chromatography-tandem mass spectrometry was developed for sensitive analysis of polychlorinated biphenyls in environmental water samples.Related important factors influencing enrichment efficiency, such as ionic strength, extraction time and amount of adsorbent, were investigated.Response surface methodology was used to optimize these factors in detail.Under the optimal conditions such as 4.92% (w/V) NaCl, 4.5 min of extraction time, 62.5 mg of adsorbent, and n-hexane as desorption solvent, wide linearity (2-1000 ng/L or 5-1000 ng/L), and low limits of detection (0.26-0.82 ng/L) were achieved.The intra-day and inter-day relative standard deviations were 0.8%-5.5% (200 ng/L, n=6)and 2.7%-7.4% (200 ng/L, n=6), respectively.Finally, this method was successfully applied to the sensitive analysis of 6 kinds of PCBs in environmental water samples, with satisfactory recoveries of 78.9%-113.3%.
RESUMEN
Objective: To develop a new method based on dispersive solid phase extraction-high performance liquid chromatography (DSPE-HPLC) for the rapid extraction, cleansing, and determination of iridoid glycosides (loganic acid, morroniside, loganin, sweroside, secoxyloganin, and secologain dimethyl acetal) in Lonicerae Japonicae Flos (LJF) and the related traditional Chinese patent medicine (TCPM) Lianhua Qingwen Capsule (LQC). Methods: Ultrasonic extraction was used for the extraction, different purification material was investigated for the rapid purification, and HPLC method was used for the determination of the content of iridoid glycosides. Results: The purification effect of LJF extract was much better by using diatomite as the purification material; The purification of LQC extract was much better by using diatomite-active carbon 80∶20. This method was simple and rapid, and has high efficiency. It could be used for the extraction, cleaning, and determination of iridoid glycosides in LJF and related prescription combined with HPLC. Conclusion: This study expands the application of DSPE in the extraction and purification of complex matrix traditional Chinese material medicine (TCMM) and TCPM, and supplies the new method and data support for the extraction and purification of bioactive compounds from complex matrix TCMM and TCPM.
RESUMEN
Abstract A method based on dispersive solid phase extraction-high performance liquid chromatography-tandem mass spectrometry for determination of 19 kinds of nonprotein nitrogen compounds including melamine, cyromazine, amidinourea, aminotriazine, 3-aminotriazole, 4-aminotriazole, allantoin, cyanuric acid, dicyandiamide, thiourea, semicarbazide, L-leucine, L-isoleucine, L-arginine, L-hydroxyproline, L-theanine, ammeline, ammelide and guanidine in powdered formulas was presented. The nonprotein nitrogen compounds were degreased by chloroform and extracted by acetonitrile, with MgSO4 to remove water and C18 to clean up. The samples were separated on Merck ZIC HILIC column (150 mm í2. 1 mm, 5 μm, 20 nm) with gradient elution. The electrospray ionization was operated in the positive mode and negative mode, and monitored by the multiple reaction monitoring ( MRM) mode. Allation was quantified by external standard method and the other 18 kinds of nonprotein nitrogen compounds were quantified by internal standard method. All of the correlation coefficients (r) were higher than 0. 99. The limits of quantitation (LOQ) were 0. 05-5. 0 mg/kg, the average recoveries were between 82 . 2% and 115 . 0%, and the relative standard deviations were less than 20%.
RESUMEN
A rapid detection method of 16 preservative residues in vegetables for export was developed by gas chromatography_mass spectrometry ( GC_MS ) after pre_treatment method of dispersive solid phase extraction ( SPE) . Samples including leafy, eggplant fruit, bean, melon and tuber vegetables were extracted with acetonitrile and detected by GC/MS with external standard method after being cleaned up with dispersive SPE. The results showed that the method had a good linearity over concentration range of 0 . 02-2 . 0 mg/L preservatives with correlation coefficients of 0 . 9990-0 . 9997 . The limits of detection ( LODs ) were in the range of 0. 004-0. 965 μg/kg. The recoveries of the preservatives were in the range of 76. 7%-120. 0% at the spiked levels of 0. 01, 0. 02 and 1. 00 mg/kg, and the relative standard deviations ( RSDs) were in the range of 2. 1%-10. 6%. Compared with the GB/T 19648_2006, etc, the method is rapid, simple, highly sensitive, and can meet testing requirements of 16 preservative residues in vegetables for export.
RESUMEN
A stimulate method for determination of polybrominated diphenyl ethers ( PBDEs) and derivatives (OH-PBDEs and MeO-PBDEs), tetrabromobisphenol A (TBBPA), hexabromocyclododecane (HBCD) in egg samples was developed by gel permeation chromatography ( GPC) and dispersive solid phase extraction ( DSPE) combined with liquid chromatography tandem mass spectrometric ( HPLC-MS/MS) and gas chroma-tography-negative chemical ionization mass spectrometry ( GC-NCI/MS ) . The analytes were extracted with mixture of hexane and dichloromethane (1∶1, V/V) by accelerated solvent extraction (ASE), and purified by 100 mg C18 dispersive solid phase extraction ( SPE) sorbents followed with gel permeation chromatography (GPC) , and then analyzed by liquid chromatography tandem mass spectrometric (HPLC-MS/MS) and gas chromatography-negative chemical ionization mass spectrometry (GC-NCI/MS), respectively. The quantita-tion was carried out external standard method. The recoveries of objects were 64. 5%-97. 2% and 65. 6%-109 . 2% ( except BDE85 was 54 . 8%, OH-BDE-137 was 47 . 4%) spiked at 1 . 0 μg/kg or 5 . 0 μg/kg in egg white and egg yolk, respectively. The relative standard deviations (RSDs) were less than 20. 2%. The limits of quantitation (LOQ) for the object were 0. 01-0. 2 μg/kg.
RESUMEN
A dispersive solid phase extraction method combined with reversed phase liquid chromatography was investigated for the determination of benzo ( a ) pyrene ( BaP ) residues in edible oil and oil products. The developed “one-step” sample preparation method integrated with the adsorbent activation, sample extraction and sample cleaning. Using Alumia-N as the adsorbent, good cleaning effect and high recovery ranging from 81. 5% -97. 5% was achieved. In addition, coupled with fluorescence detector (FLD), high sensitivity was obtained with LOD of 1. 0 μg/kg (S/N=3). Furthermore, SPSS was used to design orthogonal optimization experiments and establish the optimal condition. Under the optimized condition, the standard calibration curve was linear over the concentration range of 0. 5-10. 0μg/L, with the regression efficiency (R2) of 0. 9997. The relative standard deviation (RSD) of peak area was between 2. 6%-4. 9%, showing good repeatability and the reliability.
RESUMEN
A method was developed for simultaneous determination of pyrrolizidine alkaloids and isoquinoline alkaloids in honey by dispersive solid phase extraction and high performance liquid chromatography-tandem mass spectrometry ( QuEChERS-HPLC-MS/MS) . The honey samples were extracted with acetonitrile solution and cleaned up with PSA absorbent. Agilent Poroshell 120 SB-C18 chromatographic column was used to separate alkaloids with high sensitivity and satisfactory resolution. The identification and quantification were achieved by using electrospray ionization in positive ion mode ( ESI+) with multiple reaction monitoring (MRM). Matrix-matched calibration curves with good correlation coefficients (R2>0. 99) were obtained in the concentration range of 0. 1-100 μg/L. The recoveries of the spiked samples at 1-100 μg/kg were in the range of 70% to 110% with the RSD of intra-day and inter-day lower than 15% and 20%, respectively. The limits of detection ( LOD) and limits of quantification ( LOQ) for all alkaloids were 0. 3 and 1. 0 μg/kg, respectively. This method was successfully applied to the simultaneous determination of pyrrolizidine alkaloids and isoquinoline alkaloids for quantification and confirmation in honey samples.