液相色谱-串联质谱法同时测定食品中9种甜味剂

建立了高效液相色谱-串联质谱法同时测定食品中9种甜味剂(安赛蜜、糖精钠、甜蜜素、阿斯巴甜、三氯蔗糖、阿力甜、甜菊糖苷、爱德万甜和纽甜)含量的分析方法。样品经超声、离心等前处理后过0.22μm滤膜后上机分析。采用AQ-C18(100 mm×2.1 mm×3μm)为分离柱,c(乙酸铵)为20 mmol/L的水溶液-φ(甲酸)为0.1%的乙腈溶液为流动相,梯度洗脱,在ESI负离子模式下,采用多反应监测模式进行测定,以质量数和保留时间定性、峰面积定量。结果表明,9种甜味剂在工作曲线范围内相关系数均大于0.9990,方法检出限在0.020~0.055 mg/kg,食品加标回收率为90.6%~111.5%,其相对标准偏差(n=6)均小于6.0%。应用此方法对食品(白酒、饮料、果冻、酸奶、糖果)中9种甜味剂进行检测,前处理步骤简单,测定快速、准确度和灵敏度高,能满足国家标准对食品中9种甜味剂的分析要求,与国家标准方法相比,提高了分析效率。     

The UPLC–ESI–QqQLIT–MS/MS method for quantitative determination of phytochemicals in ethanolic extracts of different parts of eight Ficus species: Development and validation

Ficus and validation of the ultra performance liquid chromatography–electrospray ionization hybrid triple quadrupole–linear ion trap–tandem mass spectrometry (UPLC–ESI–QqQ_LIT–MS/MS) method in a multiple-reaction monitoring (MRM) mode for the quantitative determination of 19 phytochemicals. The chromatographic separation of targeted phytochemicals was performed using the Waters ACQUITY UPLC BEH? C18 column (1.7 μm, 2.1 mm × 50 mm) with 0.1% formic acid with water and acetonitrile as a mobile phase at a flow rate of 0.25 mL/min. The validation parameters showed the overall recoveries from 95.78?101.44% (RSD ≤ 3.25%), precision (intra-day: RSD ≤ 2.96%; inter-day: RSD ≤ 2.89%), linearity (R² ≥ 0.9982), limit of detection (8.60 × 10^–10?2.18 × 10^–6 mg/mL), and the limit of quantitation (2.60 × 10^–9–6.63 × 10^–6 mg/mL) in the concentration range from 0.5 to 1000 × 10^–6 mg/mL. This method was successfully applied in ethanolic extracts of different parts (fruits, leaves, and barks) of selected eight Ficus species. Quinic acid was predominant followed by rutin and chlorogenic acid among the studied nineteen phytochemicals. Ficus benjamina showed the maximum total content in fruits and leaves. The UPLC–ESI–QqQ_LIT–MS/MS method combined with principal component analysis (PCA) was successfully used for Ficus species discrimination on the basis of the contents of 15 compounds. The UPLC–ESI–QqQ_LIT–MS/MS method combined with PCA could be used for quality control.     

UPLC-ESI-MS/MS analysis of Sudan dyes and Para Red in food

An analytical method for the simultaneous determination of Sudan dyes (Sudan Red G, Sudan I, Sudan II, Sudan III, Sudan Red 7B and Sudan IV) and Para Red in food by ultra-performance liquid chromatography-electrospray tandem mass spectrometry (UPLC-ESI-MS/MS) was developed. Samples were extracted with acetonitrile, and water added into the extract. The supernatant was analysed by UPLC-MS/MS after refrigeration and centrifugation. The sample was separated on an Acquity BEH C₁₈ column, and detected by MS/MS with the multiple reaction monitoring mode. Matrix calibration was used for quantitative testing of the method. The linear matrix calibrations of Sudan dyes and Para Red were 2–50 and 10–250 ng g^?1, respectively, and the regression coefficients were >0.9945. The recoveries were 83.4–112.3% with good coefficients of variation of 2.0–10.8%. The limits of detection were between 0.3 and 1.4 ng g^?1 for the six Sudan dyes, and between 3.7 and 6.0 ng g^?1 for Para Red. The limits of quantification were between 0.9 and 4.8 ng g^?1 for the six Sudan dyes, and between 12.2 and 19.8 ng g^?1 for Para Red.     

Dissipation,residues and risk assessment of oxine-copper and pyraclostrobin in citrus

ABSTRACT

An efficient, sensitive, simple and fast method for the simultaneous determination of oxine-copper and pyraclostrobin in citrus fruit was developed and validated. The method uses ethylene diamine tetra-acetic acid as a competitive ligand to convert oxine-copper to soluble 8-hydroxyquinoline for analysis by QuEChERS and LC-MS/MS. Linear relationships were determined with correlation coefficients ranging from 0.9904 to 0.9998. The limits of detection for the analytes were 0.012–0.8 μg kg^?1, and the limits of quantitation were 0.04–2.6 μg kg^?1 in citrus. The average recoveries were 79.1–114.9% with relative standard deviations of less than 7.4%. The analyses of dissipation indicated that the half-lives of oxine-copper and pyraclostrobin were 1.94–3.67 and 1.79–2.48 days and the terminal residues were <0.08–8.99 and <0.02–1.90 mg kg^?1, respectively. The risk quotients of oxine-copper and pyraclostrobin were 0.026–0.199 and 0.003–0.022, respectively. This risk assessment provides a reference for the safe and reasonable use of oxine-copper and pyraclostrobin and may help to establish maximum residue limits for these pesticides in China.     

固相萃取-高效液相色谱-串联质谱法测定食品中的丙烯酰胺

建立高效液相色谱-串联质谱仪测定食品中丙烯酰胺含量的方法。以[D3]-丙烯酰胺为同位素内标,使用20mg/mL淀粉酶溶液对样品进行酶解,经水浴、除脂、离心,利用固相萃取柱进行净化并浓缩后,通过高效液相色谱-串联质谱仪以多选择反应监测模式进行分析测定。该方法的检出限和定量限分别为4.8μg/kg和16.5μg/kg。本方法具有操作方便、准确率高、重复性好等优点,可广泛应用于各类食品中丙烯酰胺含量的检测。     

超高效液相色谱-串联质谱法同时测定小麦粉中硫脲、曲酸、噻苯咪唑、噻二唑、四环素

建立超高效液相色谱-串联质谱法同时测定小麦粉中硫脲、曲酸、噻苯咪唑、噻二唑、四环素5 种非法添加物的快速定量检测方法。样品经80%乙醇溶液-乙腈（1∶1,V/V）提取、离心、氮吹浓缩后,采用多反应监测模式进行定性、定量分析。结果表明：本方法中硫脲、曲酸、四环素在100～5 000 ng/mL、噻苯咪唑在1～50 ng/mL、噻二唑在1～50 μg/mL范围内线性关系良好,相关系数大于0.999。硫脲、曲酸、四环素检出限为25 μg/kg,定量限为50 μg/kg;噻苯咪唑检出限为0.5 μg/kg,定量限为1 μg/kg;噻二唑检出限为0.5 mg/kg,定量限为1 mg/kg。基质添加回收率范围在88.6%～102.2%之间,相对标准偏差在0.7%～5.6%之间（n=6）。该方法前处理简单、快速,可用于小麦粉中硫脲、曲酸、噻苯咪唑、噻二唑、四环素5 种非法添加物的快速测定。     

超高效液相色谱-质谱联用法(UPLC-MS/MS)同时测定白酒中的微量甜味剂

以超纯水为提取溶剂,采用甲醇-0.02 mol/L乙酸铵溶液的流动相体系和负离子电离模式,用超高效液相色谱-三重四极杆质谱联用仪测定白酒中的安赛蜜、糖精钠、甜蜜素和三氯蔗糖。结果表明,安赛蜜、糖精钠、甜蜜素和三氯蔗糖线性范围在10～1000 ng/mL内R2大于0.9983,检出限分别为0.024 mg/kg、0.06 mg/kg、0.03 mg/kg、0.1 mg/kg,加标回收率大于82%,RSD小于2.01%。该方法简便灵敏,准确快速,可用于白酒中微量甜味剂的快速测定。     

通过式固相萃取-气相色谱-串联质谱法测定动物源性食品中11种N-亚硝胺类化合物

选取通过式固相萃取技术,结合气相色谱-串联质谱法（gas chromatography-tandem mass spectrometry,GC-MS/MS）,建立动物源性食品中11种N-亚硝胺类化合物的分析方法。样品加水浸泡后采用乙腈提取,经Prime HLB通过式固相萃取柱（200 mg/6 mL）快速净化,采用多反应监测模式监测,以空白基质匹配标准溶液外标法定量。结果表明：11种N-亚硝胺类化合物在0.5～500.0 ng/m L范围内线性关系良好,相关系数为0.999 4～0.999 8,检出限为0.2～0.3μg/kg,定量限为0.5～1.0μg/kg;在1、4、10μg/kg 3个加标水平下,11种N-亚硝胺类化合物平均加标回收率为80.1%～97.4%,相对标准偏差为2.3%～8.8%;该方法提取及净化时间仅需15 min/样品,与GB 5009.26—2016《食品安全国家标准食品中N-亚硝胺类化合物的测定》方法相比,提取与净化时间大幅缩短,检测效率提升10倍,可实现动物源性食品中N-亚硝胺类化合物的快速测定。     

基质匹配曲线校正-HPLC-MS/MS法同时测定干性食品包装纸中8 种甜味剂

建立基质匹配曲线校正-高效液相色谱-串联质谱法同时测定干性食品包装纸中安赛蜜、糖精钠、甜蜜素、三氯蔗糖、阿斯巴甜、新橙皮苷二氢查尔酮、纽甜、甜菊糖苷8 种甜味剂含量。以原纸为对象配制基质匹配溶剂，采用三乙胺缓冲溶液为萃取溶剂对样品进行超声提取，经XDB-C18色谱柱分离，甲醇-5 mmol/L乙酸铵溶液为流动相进行梯度洗脱，以电喷雾离子源正负离子切换多反应监测模式进行质谱检测，采用外标法定量。结果表明：在优化条件下，8 种甜味剂在各自质量浓度范围内线性关系良好（R2均大于0.995），检出限和定量限分别在0.13～2.50 mg/kg和0.43～8.33 mg/kg之间，加标回收率在85.49%～108.81%之间，相对标准偏差在2.24%～6.03%之间；对市售不同品牌共10 个不同规格糖果、巧克力用干性食品包装纸进行检测分析，结果显示有1 个样品中检测出含有安赛蜜和纽甜，含量分别为0.56 g/kg和0.015 g/kg。本方法具有快捷、高效、准确可靠等特点，可用于干性食品包装纸中8 种甜味剂的同时定量检测。     

Multiresidue method for the determination of 77 pesticides in wine using QuEChERS sample preparation and gas chromatography with mass spectrometry

A method based on a QuEChERS (quick, easy, cheap, effective, rugged, safe) sample preparation method and gas chromatography with mass spectrometric detection by selected ion monitoring (GC/MS-SIM) was developed for simultaneous determination of 77 pesticide residues in wine. An extraction of 10 ml of sample with acetonitrile followed by liquid–liquid partition formed by the addition of 4 g MgSO₄ and 3 g NaCl was applied in the sample preparation. The clean-up was carried out by applying dispersive solid-phase with 150 mg MgSO₄ as well as 50 mg primary secondary amine (PSA). One quantitation ion and at least two identification ions were selected in the analytical method for each pesticide compound by GC/MS. The recovery data were obtained by spiking blank samples at two concentration levels (0.05 and 0.2 mg l^?1). The recoveries of all pesticides were in the range 70–110%, with intra-day precision of less than 15%, and the inter-day precision of less than 22% and 15% for 0.05 and 0.2 mg l^?1 fortification levels, respectively. Linearity was between 0.02 and 2 mg l^?1 with determination coefficients (R ²) greater than 0.98 for all compounds. The limits of quantification (LOQs) for the 77 pesticides ranged from 0.003 to 0.05 mg l^?1. This method was applied for routine analysis in market products.     

Validation of an HPLC-DAD/UV method for the quantification of cyclamate in tabletop sweeteners: risk of exceeding the acceptable daily intake

ABSTRACT

Cyclamate is widely used as intense sweetener in the European Union. The absence of a maximum limit for the use of cyclamate in tabletop sweeteners and the growing demand for this type of product highlights the importance of developing robust analytical methods for the determination of its content to understand if the consumption of tabletop sweeteners can have a negative impact on human health. The present work aimed at the optimisation and validation of an high-performance liquid chromatography (HPLC) analytical method for cyclamate determination in tabletop sweeteners based on the procedure of European Standard EN 12857. The validated method was then applied to the determination of this sweetener in different types of tabletop sweeteners (liquid, powder and tablets). Both standards and samples solutions were submitted to a derivatisation procedure which converted cyclamate to N,N-dichlorocyclohexylamine. The derivatised product was separated and quantified using a reversed-phase column, a mobile phase composed of water (20%) and methanol (80%), isocratic flow of 1 ml min^–1, and detection by ultraviolet spectrophotometry at a wavelength of 314 nm. The analytical method was internally validated according to the following validation parameters: working range, linearity, limits of detection and quantification, sensitivity, precision (repeatability and intermediate precision), and uncertainty. This method proved to be specific and selective for the determination of this sweetener, showing repeatability, RSD_r ≤ 3%, intermediate precision, RSD_R ≤ 3.3%, and recovery rates from 92% to 108% for the different tabletop sweeteners. The method uncertainty was 9.4%. The concentration of cyclamate in the samples varied significantly, from 2.9% to 73.9%, which demonstrated that a possible excessive consumption of one of the analysed sweeteners can lead to exceeding the acceptable daily intake for cyclamate.     

Fast analysis of caffeinated beverages using laser diode thermal desorption mass spectrometry (LDTD-MS/MS)

ABSTRACT

A rapid method for quantitative caffeine analysis in carbonated and non-carbonated beverages and liquid dietary supplement products was developed based on the direct sample introduction technique of laser diode thermal desorption atmospheric pressure chemical ionisation with tandem mass spectrometry (LDTD-MS/MS). Product samples were diluted with a mixture of methanol, water, and d₃-caffeine internal standard. Sample aliquots were filtered, spotted on a metal-lined LDTD microtitre plate, dried, and thermally desorbed for subsequent ionisation and analysis by MS/MS analysis. Each sample required a 6 s desorption, and sample-to-sample analysis time of less than 30 s per sample. Caffeine yielded a linear calibration curve over the range 0.5–100 μg mL^?1 (R² > 0.995). Caffeine recoveries from fortified samples ranged from 97% to 107% with <5% RSD. The caffeine determination was not affected by matrix interferences despite the large range of ingredients, vitamins, sweeteners, extracts, and additives present in the products tested, even though LDTD-MS/MS is a whole-sample desorption technique with no separation of matrix background. The method detection limit was below 0.12 μg mL^?1. The method was applied to 33 caffeinated products and LDTD-MS/MS quantitative results closely correlated (R² > 0.998) with the regulatory standard HPLC-UV method (AOAC Official Method 979.08).     

Simultaneous Determination of Ractopamine,Chloramphenicol, and Zeranols in Animal-Originated Foods by LC-MS/MS Analysis with Immunoaffinity Clean-up Column

A novel analytical method employing immunoaffinity column (IAC) clean-up coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for simultaneous determination of ractopamine, chloramphenicol, and zeranols (α-zearalanol, β-zearalanol, zearalanone, α-zearalenol, β-zearalenol, and zearalenone) in animal-originated foods. The sample was first digested by β-glucuronidase/sulfatase and then extracted with ethyl acetate-diethyl ether (9:1, v/v). The extracted solution was evaporated to dryness and then the residue was dissolved by 2 mL of 50% acetonitrile solution. After filtration, 1 mL filtrate was diluted to 10 mL with PBS. The reconstituted solution was cleaned up with immunoaffinity column and then analyzed by high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). The established method was shown to be sensitive efficient and reliable as indicated by the linearity (r ² ≥ 0.9994), precision (RSD ≤ 1.7%), average recovery (72.3–103.2%), and the limit of detection (0.05–0.10 μg/kg). The method can be used for determination of trace residues of ractopamine, chloramphenicol, and zeranols in animal-originated foods.     

新型在线净化前处理HPLC-MS/MS测定香精香料中的麦角甾醇和麦角甾酮

建立一种新型的在线净化前处理装置结合高效液相色谱-串联质谱（high performance liquid chromatography-tandem with mass spectrometry,HPLC-MS/MS）法测定香精香料中的麦角甾醇和麦角甾酮。该前处理装置结合基质分散萃取和柱层析对样品进行萃取和净化,之后对样品进行浓缩并利用HPLC-MS/MS分析测定。HPLC-MS/MS方法以甲醇和水为流动相,0.4?mL/min流速条件下梯度洗脱,采用C18色谱柱进行液相色谱分离,大气压正离子方式电离,多重反应监测模式检测,内标法进行定量分析。结果表明,该方法前处理方便且稳定性强,溶剂可回收,净化萃取浓缩为一体;目标物质麦角甾醇和麦角甾酮能在5?min内得到分离检测,在1.5～250?μg/mL范围内具有较好的线性,各待测物的线性相关系数均大于0.999,检出限为0.32～0.35?μg/mL,在不同添加水平条件下,平均回收率为86%～96%,相对标准偏差在3.1%～3.6%之间。本方法能较好地应用于香精香料实际样品中麦角甾醇和麦角甾酮的测定。     

高效液相色谱-串联质谱法测定猪肉及猪肉制品中牛磺酸含量

建立猪肉及猪肉制品中牛磺酸含量的高效液相色谱-串联质谱(high performance liquid chromatography-tandem mass spectrometry,HPLC-MS/MS)检测方法.样品经水超声提取后,经乙腈沉淀蛋白,正己烷除脂肪,采用HPLC-MS/MS法定量测定.结果 表明:在1～...     

Quantification of mycotoxins in vegetable oil by UPLC-MS/MS after magnetic solid-phase extraction

ABSTRACT

The detection of mycotoxin contamination in foodstuffs is highly significant for public health. Herein we report an analytical method based on magnetic solid-phase extraction (MSPE) and UPLC-MS/MS for the simultaneous determination of mycotoxins, including fumonisins B₁ (FB₁), zearalenone (ZON) and ochratoxin A (OTA), in vegetable oil. Magnetic nanoparticles coated with double layers of silicon dioxide were synthesised and found to be an effective MSPE adsorbent for mycotoxins. The proposed MSPE procedure serves not only for sample clean-up but also for mycotoxin enrichment that enhances greatly the assay’s sensitivity. Under the selected MSPE conditions, linear matrix-matched calibration curves were obtained for mycotoxins in a concentration range from 0.178 to 625 μg kg^–1. The limits of detection were 0.210 μg kg^–1 for FB₁, 0.0800 μg kg^–1 for OTA and 1.03 μg kg^–1 for ZON. The proposed MSPE UPLC-MS/MS method was applied for the determination of mycotoxins in vegetable oil samples, including maize oil, rapeseed oil and soybean oil. ZON was detected in a maize oil at 101 μg kg^–1, which is below the European Union limit of 200 μg kg^–1 in foodstuffs.     

Improved method for the determination of 12 non-nutritive sweeteners and monitoring in various foods using liquid chromatography–tandem mass spectrometry

An improved and highly sensitive method was developed and validated for the determination of 12 (7 permitted and 5 non-permitted in Korea) non-nutritive sweeteners in various foods using liquid chromatography-electrospray ionisation-tandem mass spectrometry. The chromatographic separation was performed on an Xbridge BEH C18 column (3 mm × 100 mm, 2.5 μm) with gradient elution using 10 mM ammonium acetate in water and 10 mM ammonium acetate in methanol. Sample preparation consisted of simple dilution, homogenisation, centrifugation and purification with a C18 cartridge prior to analysis. The relative matrix effect (%ME) was within ±20% for all sweeteners. The method also showed good linearity (R² > 0.99). The limit of detection and limit of quantification values in sample were in the range of 0.02–2.66 and 0.06–8.05 mg kg^?1, respectively. The recoveries at three concentration levels ranged between 80% and 119%, with relative standard deviation values below 10%. In addition, the expanded uncertainties determined for 12 sweeteners in 5 different food matrices were confirmed to be <14%. Finally, the method was successfully applied to the analysis of sweeteners in 681 food samples purchased in Korea, Australia and Turkey. These results demonstrate that the method is suitable for the simultaneous determination of multiple-sweeteners in a variety of foods.     

UPLC-MS/MS法测定葡萄干中6种人工合成甜味剂

该试验旨在建立超高效液相色谱-串联质谱(UPLC-MS/MS)测定葡萄干中安赛蜜、糖精钠、甜蜜素、阿斯巴甜、阿力甜和纽甜6种人工合成甜味剂的测定方法。样品经0.1%甲酸水提取,采用C₁₈色谱柱分离,以0.05%甲酸水和乙腈作为流动相进行梯度洗脱。采用电喷雾离子化,负离子扫描和多反应监测模式(MRM)检测,外标法定量。结果表明,6种甜味剂在1~200 ng/mL范围内线性关系良好,相关系数均大于0.99。6种甜味剂的方法检出限为1~2μg/kg,方法定量限为2.5~5μg/kg;在10,20和100μg/kg 3个添加水平下,平均回收率在81.5%~106.7%之间,相对标准偏差为1.7%~6.9%(n=6)。该方法简单、灵敏度高、分析时间短,适用于葡萄干中6种人工合成甜味剂的测定。     

Development of a chemometric-assisted deep eutectic solvent-based microextraction procedure for extraction of caffeine in foods and beverages

ABSTRACT

In this research article, a novel and green deep eutectic solvent-based microextraction (DES-ME) procedure based on chemometric-assisted (CA) optimization was developed for the extraction of caffeine in foods and beverages prior to its spectrophotometric determination. Ultrasound was used to accelerate the extraction of caffeine. Deep eutectic solvents (DES), prepared in an ultrasonic bath at 20–60 min for 60–80°C, were used as extraction solvents. The important experimental variables (pH, DES amount, temperature, sonication time and metal concentration) were modelled and optimized using response surface methodology (RSM) based on central composite design (CCD). Under the optimum conditions, the proposed method allowed the determination of caffeine with limits of detection (LOD, 3s_blank/m) and quantification (LOQ, 3s_blank/m) of 7.5 and 25.0 µg L^?1, respectively. For 40 µg L^?1 and 100 µg L^?1 of caffeine (n = 5), relative standard deviations (RSDs%) and recoveries% were 1.2–1.6% and 96.7–98.2%, respectively. Validation studies (accuracy, precision, trueness, reliability and selectivity) of the method were performed before the analysis of real samples. The results showed that the combination of the CCD with the DES-ME can be considered as a new perspective for the extraction and determination of caffeine in foods and beverages.     

HPLC-MS/MS-Detection of Caseins and Whey Proteins in Meat Products

Screening methods for the mass spectrometric detection of caseins and whey proteins in meat products have been developed. After tryptic digestion, two α-S1-casein and two β-lactoglobulin marker peptides were measured by HPLC-MS/MS. For matrix calibrations, emulsion-type sausages with different concentrations of milk and whey protein (ppm level) were produced. The limits of detection (LODs) were below 1 ppm for milk protein and about 3 ppm for whey protein. The determination coefficients for the correlation between peak area of the marker peptides and the concentrations of milk and whey proteins were R²≥0.9899.