QuEChERS Purification Research Articles

Determination of new glucocorticoid called clobetasol acetate in cosmetics by ultra performance liquid chromatography-tandem mass spectrometry

At present, new prohibited substances are becoming more common illegal additions in cosmetics. Clobetasol acetate is a new glucocorticoid, which is not covered in the current national standards and is a homologue of clobetasol propionate. A method was established for the determination of clobetasol acetate as a new glucocorticoid (GC) in cosmetics by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Five common cosmetic matrices were suitable for this new method: creams, gels, clay masks, masks and lotions. Four pretreatment methods were compared: direct extraction by acetonitrile, PRiME pass-through column purification, solid-phase extraction (SPE) purification, and QuEChERS purification. Further, the effects of different extraction efficiencies of the target compound, such as extraction solvents and extraction time, were investigated. The MS parameters, such as ion mode, cone voltage and collision energy of ion pairs of the target compound, were optimized. The chromatographic separation conditions and response intensities of the target compound in different mobile phases were compared. Based on the experimental results, the optimal extraction method was determined to be direct extraction, wherein the samples were vortex dispersed with acetonitrile, ultrasonic extraction over 30 min and filtered by a 0.22 μm organic millipore filter, and then the samples were detected by UPLC-MS/MS. The concentrated extracts were separated on a Waters CORTECS C18 column (150 mm×2.1 mm, 2.7 μm), where the water and acetonitrile were used as the mobile phases for gradient elution. The target compound was detected with the multiple reaction monitoring (MRM) mode under electrospray ionization and positive ion scanning (ESI+). Quantitative analysis was performed by matrix matching standard curve. Under the optimum conditions, the target compound had good linear fitting in the range of 0.9-37 μg/L. The linear correlation coefficient (R2) was greater than 0.99, the limit of quantification (LOQ) of the method was 0.09 μg/g and the limit of detection (LOD) was 0.03 μg/g for these five different cosmetic matrices. The recovery test was conducted under three spiked levels: 1, 2 and 10 times of LOQ. The recoveries of the tested substance were between 83.2% and 103.2% in these five cosmetic matrices, and the relative standard deviations (RSDs, n=6) were between 1.4% and 5.6%. This method was used to screen cosmetic samples of different matrix types, and a total of five positive samples were found, in which the content range of clobetasol acetate was from 1.1 to 48.1 μg/g. In conclusion, the method is simple, sensitive and reliable, and is suitable for high-throughput qualitative and quantitative screening, and the analysis of cosmetics with different matrix types. Moreover, the method provides crucial technical support and a theoretical basis for the establishment of feasible detection standards for clobetasol acetate in China, as well as for the control of the compound in cosmetics. This method has important practical significance to implement management measures of illegal additions in cosmetics.

Modified QuEChERS combined with UPLC-MS/MS to determine eight biogenic amines in Xinjiang smoked horsemeat sausages

A modified QuEChERS method coupled with ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was established for the simultaneous determination of eight biogenic amines (BAs) in Xinjiang smoked horsemeat sausages. The conditions of UPLC-MS/MS, extraction solvent and QuEChERS purification were optimized. The internal standard method was used for quantitative analysis. Results showed that the eight BAs exhibited good linearity (1-200 μg/L, correlation coefficient > 0.99). The limits of detection and quantification were 5 μg/kg and 10 μg/kg, respectively. The accuracy was between 80.4% and 111.4%, and the precision was less than 10%. The established method was effectively used for the determination of eight BAs in forty Xinjiang smoked horsemeat sausages. Results showed that tyramine was the major amine, followed by cadaverine, putrescine and spermine. Total BAs content ranged from 26.5 mg/kg to 352.9 mg/kg, the contents of BAs in Xinjiang smoked horsemeat sausages may pose a potential health risk.

Determination of 31 pesticide residues in wolfberry by LC-MS/MS and dietary risk assessment of wolfberry consumption

A modified QuEChERS method coupled with LC-MS/MS was developed and validated to detect 31 pesticides in wolfberry. The conditions for extraction solvent and QuEChERS purification were optimized. The validated method was applied to analyse pesticides in 200 wolfberry samples. The risk from chronic and acute dietary intake of the detected pesticide residues was assessed by the acceptable daily intake (ADI) and acute reference dose (ARfD), respectively, and the cumulative intake risk posed by the detected residues was assessed by the hazard index (HI). The results showed that 23 pesticides were detected in all wolfberry samples. The risk from chronic dietary intake was between 0.0001% and 1.6067%, and the risk from acute dietary intake was between 0.0010% and 0.4999%, which were all far below 100%. The HI was 0.02569 for chronic dietary intake and 0.015164 for acute dietary intake, which were both far below 1. The results indicated that the pesticide residues in wolfberry would not cause potential risk to human health. This work not only enhances our understanding of the potential exposure risks of pesticide residues in wolfberry, but also provides an effective method for the risk assessment of pesticide residues in other agricultural products.

Transfer rates on nine pesticides from dry tea to infusion by QuEChERS purification followed by LC-MS/MS analysis

ABSTRACT In this study, the transfer rates of nine pesticides with different water solubility (imidaclothiz, acetamiprid, thiamethoxam, imidacloprid, clothianidin, carbendazim, pyraclostrobin, phoxim and etoxazole) from dry tea to infusion were carefully determined using the liquid-chromatography-tandem mass spectrometry (LC-MS/MS). The obtained results show that the transfer of each pesticide from tea spiked with the pesticides to the infusion ranged from 4.54% (etoxazole) to 58.0% (acetamiprid) under the traditional brewing condition in China, which indicates that transfer of pesticides was dependent on their water solubilities. Increases in infusion time resulted in increased transfer within 30 min. However, there was little influence of infusion time on transfer rates after 30 min. When the infusion temperature was between 50 and 100°C, the transfer rates of acetamiprid, thiamethoxam, imidacloprid, carbendazim, pyraclostrobin, phoxim and etoxazole increased with temperature, while transfer rates for imidaclothiz and clothianidin decreased with increasing temperature. After three infusions, the transfer rates of imidaclothiz, thiamethoxam, acetamiprid, and clothianidin were >70%. Our results provide a basis for the rational use of pesticides in tea gardens and a reasonable evaluation of dietary exposure levels of pesticide residues in brewed tea.

QuEchERS pretreatment coupled to gas chromatography and tandem mass spectrometry to fast determination of 34 pesticide residues in Glycyrrhizae Radix et Rhizoma

This study proposed a quantitative method for 34 pesticides including organochlorine,organophosphorus and pyrethroids in Glycyrrhizae Radix et Rhizoma herbs and medicinal slices,and analyzed the pesticide residues of collected Glycyrrhizae Radix et Rhizoma samples from different regions. With acetonitrile extraction and optimized Qu Ech ERS purification,the 32 batches of Glycyrrhizae Radix et Rhizoma herbs and medicinal slices were analyzed by matrix matching standard curve quantitative analysis under GC-MS/MS multi-response monitoring( MRM) mode. This study investigated the pretreatment of Glycyrrhizae Radix et Rhizoma samples based on the Qu Ech ERS method of Chinese Pharmacopoeia( 2015 edition,4),and the result showed that the recoveries of some pesticide was low and pigment has a strong interference in analysis,which result in worse purification effect. Therefore,this paper further optimized the Qu Ech ERS method and corrected the matrix matching standard curve method,and compensated the qualitative and quantitative effects of matrix effects on the detected target compounds in Glycyrrhizae Radix et Rhizoma. The results showed that 34 kinds of pesticide had good linear( R~2 of 0. 996 4 or higher) within a covering 0. 01-0. 2 mg·kg~(-1) concentration range. The limits of quantitation are less than 0. 01 mg·kg~(-1). This method was further applied to the simultaneous determination of 34 pesticide residues of typical organochlorine,organophosphorus and pyrethroids in 32 batches of Glycyrrhizae Radix et Rhizoma herbs and medicinal slices. Six batches containing beta-endosulfan,thiosulphate,o,p'-DDD and thrta-cypermethrin were detected,but none of them exceeded the limit of pesticide residues stipulated in the Chinese Pharmacopoeia and the EU Pharmacopoeia. This study indicates that the established method is rapid,convenient,accurate,and sensitive,which provides a rapid and efficient method for the simultaneous determination of typical organochlorine,organophosphorus and pyrethroids in Glycyrrhizae Radix et Rhizoma.

QuEChERS Purification with HPLC-MS/MS for Rapid Confirmation in Acute Clenbuterol Poisoning Case Sample

QuEChERS Purification with HPLC-MS/MS for Rapid Confirmation in Acute Clenbuterol Poisoning Case Sample

Simultaneous determination of allopurinol, probenecid, benzbromarone in dietary supplements by ultra high performance liquid chromatography-tandem mass spectrometry

A method based on QuEChERS purification was developed for the simultaneous determination of allopurinol, probenecid and benzbromarone in anti-gout dietary supplements by ultra high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The samples were extracted by acetonitrile mixed with 0.1% (v/v) ammonium hydroxide, and the extracts were purified using primary secondary amine (PSA) and C18 adsorbents. The samples were separated on a C18 chromatographic column with the gradient elution of 0.1% (v/v) formic acid aqueous solution and methanol as mobile phases. The analytes were detected by a electrospray ionization source in the positive or negative ion mode and the multiple reaction monitoring mode. The results showed that the limits of detection of allopurinol, probenecid and benzbromarone were 5, 25 and 25 μg/kg, and the limits of quantification were 17, 80 and 80 μg/kg. The average spiked recoveries of the three chemical drugs in dietary supplements were in the range of 76.8%-116.6% with the relative standard deviations of 2.7%-14.6%. The proposed method was applied for the analysis of 68 dietary supplements, and allopurinol was detected in one of them. This method is simple and sensitive, and can be used for the determination of the allopurinol, probenecid and benzbromarone in anti-gout dietary supplements.

Rapid determination of six banned fragrance components in tea by QuEChERS-gas chromatography-tandem mass spectrometry

QuEChERS purification was established as a sample pretreatment method and combined with gas chromatography-tandem mass spectrometry (GC-MS/MS) for the simultaneous detection of six banned fragrance components in tea (coumarin, thujone, 2-exylthiophene, trans-beta-acacene, p-mentha-1,8(10)diene-9-ethyl acetate, and butyl cinnamate). Tea samples were extracted with ethyl acetate and subjected to whirlpool oscillation, following which anhydrous magnesium sulfate, primary secondary amine (PSA), and octadecylsilyl silica gel (C18) were added to the supernatant. After centrifugation, the supernatant was filtered over a membrane and separated on a DB-5MS column. The six compounds were determined by GC-MS/MS in MRM mode, and quantified by a matrix-matched external standard method. The six banned flavor compounds exhibited good linearity over the range of 1-200 μg/L, and the linear correlation coefficients (R2) were greater than 0.999. The limits of detection were 0.005-1 μg/kg and the limits of quantification were 0.02-2 μg/kg, the average recoveries were 82.3%-93.1%, and the intra-day and inter-day RSDs were each less than 10%. The method is simple, rapid, accurate, and sensitive, and can be used for the simultaneous detection of six banned fragrance components in tea.

Determination of eight antifungal drugs in mutton by QuEChERS coupled with ultra-performance liquid chromatography-tandem mass spectrometry

A method for the simultaneous determination of eight antifungal drugs in mutton was developed using QuEChERS combined with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The samples were shaken with acetonitrile containing 2.0% (v/v) formic acid, and then subjected to QuEChERS purification. The residual targets were analyzed on an Atiantis® T3 column (100 mm×2.1 mm, 3 μm) with gradient elution using acetonitrile-0.1% (v/v) formic acid aqueous solution as the mobile phase. All the analytes were effectively separated and cleaned up within 9 min, and were finally detected by UPLC-MS/MS with ESI+ ionization in multiple reaction monitoring (MRM) mode. All the eight antifungal drugs showed a good linear trend in the range of 0.2-50 μg/L, with the correlation coefficient (R2) greater than 0.99. The limits of detection (LODs) and limits of quantification (LOQs) were 0.3-3.0 μg/kg and 1.0-10.0 μg/kg, respectively. The calibration curves were used in the analysis to reduce the negative influence of matrix effects. The average recoveries at different levels (low, medium, and high) for all the analytes ranged from 70.3% to 118.4%, with the relative standard deviations of 0.4%-4.3% (n=6). The developed method shows excellent recovery and stable repeatability, and is suitable for the determination of the antifungal drugs in mutton.

Factors influencing the extraction of pharmaceuticals from sewage sludge and soil: an experimental design approach.

Pharmaceuticals can enter the environment when organic waste products are recycled on agricultural soils. The extraction of pharmaceuticals is a challenging step in their analysis. The very different extraction conditions proposed in the literature make the choice of the right method for multi-residue analysis difficult. This study aimed at evaluating, with experimental design methodology, the influence of the nature, pH and composition of the extraction medium on the extraction recovery of 14 pharmaceuticals, including 8 antibiotics, from soil and sewage sludge. Preliminary experimental designs showed that acetonitrile and citrate-phosphate buffer were the best extractants. Then, a response surface design demonstrated that many cross-product and squared terms had significant effects, explaining the shapes of the response surfaces. It also allowed optimising the pharmaceutical recoveries in soil and sludge. The optimal conditions were interpreted considering the ionisation states of the compounds, their solubility in the extraction medium and their interactions with the solid matrix. To perform the analysis, a compromise was made for each matrix. After a QuEChERS purification, the samples were analysed by online SPE-UHPLC-MS-MS. Both methods were simple and economical. They were validated with the accuracy profile methodology for soil and sludge and characterised for another type of soil, digested sludge and composted sludge. Trueness globally ranged between 80 and 120% recovery, and inter- and intra-day precisions were globally below 20% relative standard deviation. Various pharmaceuticals were present in environmental samples, with concentration levels ranging from a few micrograms per kilogramme up to thousands of micrograms per kilogramme. Graphical abstract Influence of the extraction medium on the extraction recovery of 14 pharmaceuticals. Influence of the ionisation state, the solubility and the interactions of pharmaceuticals with solid matrix. Analysis of different soils and organic waste products.

Simultaneous Determination of Four Herbicide and Pesticide Residues in Chinese Green Tea Using QuEChERS Purification Procedure and UPLC-MS/MS Analysis

A method for simultaneous determination of residuals of four herbicides and pesticides, simazine, carboxin, diflubenzuron and rotenone, in Chinese green tea was developed. In the proposed method, the tea powder was placed in a centrifuge tube with a plug, extracted in saturated aqueous sodium chloride solution and acetonitrile, agitated using vortex oscillator, and then centrifuged 5 min at 4000 rpm. The supernatant solution was purified by primary secondary amine (PSA) sorbent, C18 power, and graphitized carbon black powder, respectively. Then the purified extracts were dissolved with acetonitrile:0.1% formic acid aqueous solution (40:60, V/V) and agitated, filtered using a syringe with 0.22 μm nylon filter prior to UPLC-MS/MS analysis. The UPLC analysis was performed on an ACQUITY UPLC® HSS T3 column (2.1 mm×100 mm, 1.8 µm), using acetonitrile-0.1% formic acid as mobile phase with the flow rate as 0.3 mL•min-1. Injection volume was 10 µL. Positive ionization mode was applied, and the ions were monitored in the multiple reaction monitoring (MRM) mode with curtain gas 0.069 MPa, collision gas 0.052 MPa, ESI ion spray voltage 5000 V, temperature 550 °C, nebulizer gas 0.24 MPa, and turbo gas 0.28 MPa. The limit of detection (LOD) and limit of quantitation (LOQ) of the proposed method are 1 μg•kg-1and 5 μg•kg-1, respectively. The average recoveries of the four pesticides at 10, 20, and 50 µg•kg-1spiking levels range from 77.4% to 95.3%. TheSupersSuperscript textcript textrelative standard deviation (RSD) (n=6) range form 11.83% to 4.52%.