Phase Extraction-ultra Performance Liquid Chromatography-tandem Research Articles

Simultaneous determination of 61 hormones in water by solid phase extraction-ultra performance liquid chromatography-tandem mass spectrometry

Concerns over the emergence of steroid hormones as pollutants in water have grown. Steroid hormone compounds present challenges in the simultaneous detection of total residual hormones owing to their analogous structures and diverse types. In this study, we established a rapid and high-throughput continuous online method based on solid phase extraction (SPE) coupled with ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) for the simultaneous determination of 61 hormone components, including 48 glucocorticoids, 1 mineralocorticoid, 4 androgens, and 8 progesterones, in water. Various SPE columns were investigated to assess their extraction efficiency for enriching and purifying target compounds in a large sample volume (1 L). An HC-C18 SPE column was selected because of its superior performance. Acetonitrile was used as a washing solution during SPE to ensure that the majority of the tested substances achieved recoveries exceeding 70% and effectively avoid interferences from water-soluble components. Various C8 and C18 columns were tested, and the optimal HPLC conditions for hormone retention were established. We systematically evaluated different UPLC columns and mobile phases, including methanol-water and acetonitrile-water systems with 0.1% formic acid added to the aqueous phase. The optimized UPLC conditions were as follows: BEH C18 column (100 mm×2.1 mm, 1.7 μm); column temperature, 40 ℃; flow rate, 0.3 mL/min; injection volume, 5 μL; mobile phase A: 0.1% formic acid aqueous phase; mobile phase B: acetonitrile. Gradient elution was performed as follows: 0-0.5 min, 30%B; 0.5-15.0 min, 30%B-75%B; 15.0-18.0 min, 75%B-98%B; 18.0-19.0 min, 98%B; 19.0-19.1 min, 98%B-30%B; 19.1-20.0 min, 30%B. Both positive- and negative-ion modes were explored in the UPLC-MS/MS experiment to obtain the full scan of the parent ions, and positive mode was finally selected for electrospray ionization (ESI). Two product ions exhibiting strong signals and minimal interference were selected for quantitative and qualitative ion analyses, using an external standard method for quantification. MS/MS was performed in positive-ion (ESI+) mode with multiple reaction monitoring (MRM) scanning. The MS/MS parameters were as follows: atomizing gas pressure, 379 kPa; curtain air pressure, 241 kPa; spray voltage, 5500 V; desolvation temperature, 550 ℃; collision exit voltage (CXP), 13 V; intake voltage (EP), 10 V; and residence time of each ion pair, 0.5 ms. Other instrument settings, such as the collision energy and declustering voltage, were also optimized. The 61 hormones exhibited excellent linear relationships within their corresponding concentration ranges, with correlation coefficients greater than 0.99. The method detection limits (MDLs) were in the range of 0.05-1.50 ng/L. The average recoveries of the 61 hormones across three spiked levels ranged from 62.3% to 125.2%, with relative standard deviations (RSDs, n=6) of 1.1%-10.5%. Using this method, we successfully detected 10 hormone components (cortisone, fluticasone propionate, ciclesonide, betamethasone dipropionate, clobetasone butyrate, diflucortolone valerate, halobetasol propionate, isoflupredone, difluprednate, and hydroxyprogesterone caproate) in various surface water and groundwater samples collected from the Taihu Basin region. The SPE-UPLC-MS/MS method presented in this paper is simple, highly sensitivity, and exceptionally accurate. Thus, it exhibits promising potential for tracing targeted hormone residues in water and will be of great value in monitoring and ensuring water safety. Finally, a regional analysis was conducted on the hormone levels in water, and suggestions were made for the targeted treatment of hormone residues in future sewage treatment processes.

Determination of beauvercin and enniatins in rice flour and wheat flour by solid phase extraction-ultra performance liquid chromatography-tandem mass spectrometry

To develop a method for the determination of beauvercin(BEA), enniatin A(ENNA), enniatin A1(ENNA1), enniatin B(ENNB) and enniatin B1(ENNB1) in rice flour and wheat flour by ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS). Samples were extracted by acetonitrile-water, purified by Oasis Prime HLB solid-phase extraction column. The sample solution was separated by waters BEH C_(18) column(2.1 mm×100 mm, 1.8 μm). The detection was performed in the electrospray positive ionization(ESI+) under multiple reaction monitoring(MRM) mode. The internal standard method and the matrix-matched calibrations were used for quantification. The linear relationships of BEA and 4 kinds of enniatins(ENNs) were good in the range of 0.1-50.0 ng/mL(r>0.999). The average recoveries of BEA and ENNs in rice flour and wheat flour were 96.4%-105.4% and 99.1%-109.2%, with the relative standard deviations(RSD) of 1.01%-7.42% and 1.09%-9.69%(n=6). The detection limits(LOD) of BEA and ENNs were 0.03 μg/kg. The quantitative limits(LOQ) of BEA and ENNs were 0.1μg/kg. The matrix induced suppression or enhancement effect were 72.7%-99.3% and 60.8%-100.4%, respectively. The levels of emerging BEA and ENNs in wheat flour were higher than rice flour. The detection rate of enniatin B was highest in wheat flour and rice flour, the contents were 0.03-9.57 μg/kg and 0.03-0.56 μg/kg, the positive percentage were 98.5% and 36.4%. The method is quick, easy, accurate and sensitive, which is suitable for the determination of BEA and 4 kinds of ENNs in rice flour and wheat flour.

Simultaneous determination of 43 antibacterials from nine categories in water using automatic sample loading-solid phase extraction-ultra performance liquid chromatography-tandem mass spectrometry

Antibacterials represent a pharmaceutical class that is extensively used and consumed worldwide. The presence of a large number of antibacterial agents in water could result in antibiotic resistance. Thus, the development of a fast, accurate, and high-throughput method to analyze these emerging contaminants in water is necessary. Herein, a method was developed to achieve the simultaneous determination of 43 antibacterials from nine pharmaceutical categories (i.e., sulfonamides, quinolones, fluoroquinolones, tetracyclines, lincosamides, macrolides, nitroimidazoles, diterpenes, and dihydrofolate reductase inhibitors) in water using automatic sample loading-solid phase extraction (SPE)-ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Because the properties of these 43 antibacterials are quite different, the main objective of this work is to develop an extraction procedure that would enable the simultaneous analysis of a wide range of multiclass antibacterials. Given this context, the work presented in this paper optimized the SPE cartridge type, pH, and sample loading amount. Multiresidue extraction was performed as follows. The water samples were filtered through 0.45 μm filter membranes, added with Na2EDTA and NaH2PO4, and pH-adjusted to 2.34 using H3PO4. The solutions were then mixed with the internal standards. An automatic sample loading device fabricated by the authors was used for sample loading, and Oasis HLB cartridges were used for enrichment and purification. The optimized UPLC conditions were as follows: chromatographic column, Waters Acquity UPLC BEH C18 column (50 mm×2.1 mm, 1.7 μm); mobile phases, methanol-acetonitrile (2∶8, v/v) solution containing 0.1% formic acid and 0.1% formic acid aqueous solution; flow rate, 0.3 mL/min; injection volume, 10 μL. The compounds were step scanned using an electrospray ionization source in the positive and multiple-reaction monitoring (MRM) modes, and analyzed by internal and external standard methods. The results showed that the 43 compounds achieved high linearity in their respective linear ranges, with correlation coefficients (r2) greater than 0.996. The limits of detection (LODs) of the 43 antibacterial agents ranged from 0.004 ng/L to 1.000 ng/L, and their limits of quantification (LOQs) ranged from 0.012 ng/L to 3.000 ng/L. The average recoveries ranged from 53.7% to 130.4%, and the relative standard deviations (RSDs) were between 0.9% and 13.2%. The method was successfully applied to the determination of six tap water samples from different districts and six water samples obtained from the Jiangyin section of the Yangtze River and Xicheng Canal. No antibacterial compound was detected in any of the tap water samples, but a total of 20 antibacterial compounds were detected in the river and canal water samples. Among these compounds, sulfamethoxazole showed the highest mass concentrations, ranging from 8.92 to 11.03 ng/L. The types and contents of antibacterials detected in the Xicheng Canal were greater than those found in the Yangtze River, and two kinds of diterpenes, namely tiamulin and valnemulin, were found easily and commonly in water sample. The findings indicate that antibacterial agents are widespread in environmental waters. The developed method is accurate, sensitive, rapid, and suitable for the detection of the 43 antibacterial compounds in water samples.

Uncovering an Emerging Group of Halogenated Nucleobase-Derived Disinfection Byproducts in Drinking Water: Prioritization of the Highly Cytotoxic 2-Chloroadenine.

Constant efforts have been devoted to exploring new disinfection byproducts in drinking water causally related to adverse health outcomes. In this study, five halogenated nucleobases were identified as emerging disinfection byproducts in drinking water, including 5-chlorouracil, 6-chlorouracil, 2-chloroadenine, 6-chloroguanine, and 5-bromouracil. We developed a solid phase extraction-ultraperformance liquid chromatography-tandem mass spectrometry method with the limits of detection (LOD) and recoveries ranging between 0.04-0.86 ng/L and 54-93%, respectively. The detection frequency of the five halogenated nucleobases ranged from 73 to 100% with a maximum concentration of up to 65.3 ng/L in the representative drinking water samples. The cytotoxicity of the five identified halogenated nucleobases in Chinese hamster ovary (CHO-K1) cells varied with great disparity, in which the cytotoxicity of 2-chloroadenine (IC50 = 9.4 μM) is appropriately three times higher than emerging DBP 2,6-dichloro-1,4-benzoquinone (IC50 = 42.4 μM), indicating the significant toxicological risk of halogenated nucleobase-DBPs. To the best of our knowledge, this study reports the analytical method, occurrence, and toxicity of halogenated nucleobase-DBPs for the first time. These findings will provide a theoretical basis for further research on probing the relationship between its mutagenicity and human health risk.

Determination of five nonsteroidal anti-inflammatory drugs in water by dispersive solid phase extraction-ultra performance liquid chromatography-tandem mass spectrometry based on metal-organic framework composite aerogel

非甾体类抗炎药(NSAIDs)能在环境水体中长期稳定存在,不仅对生物有慢性毒性还能增加病原体的耐药性,开发可靠的测定水样中痕量非甾体抗炎药的分析方法至关重要。该文制备新型金属有机骨架/壳聚糖复合气凝胶材料Co-UiO-67(bpy)/CS分散固相萃取吸附剂,将其用于环境水体中酮洛芬、萘普生、氟比洛芬、双氯芬酸、布洛芬5种非甾体类抗炎药的富集,结合超高效液相色谱-串联质谱法(UPLC-MS/MS),建立了基于金属有机骨架材料(MOFs)复合气凝胶环境水体中药物残留检测的新方法。为获得最佳的萃取效率,对影响萃取效果的主要因素(材料类型、MOFs用量、萃取时间、水样pH值、离子强度、甲酸体积分数、洗脱时间、洗脱剂体积)进行条件考察及优化。优化结果显示,吸附剂5 min内就可实现目标化合物的完全吸附,用总体积为5 mL的1%甲酸甲醇溶液洗脱6 min,目标化合物就能充分解吸。在最优的固相萃取条件下建立分析方法,结果表明,5种非甾体类抗炎药在各自范围内线性关系良好,线性相关系数均大于0.9937,方法的检出限(LOD)和定量限(LOQ)分别为0.32~2.06 ng/L和1.05~6.78 ng/L。在40、250和1500 ng/L 3个加标水平下进行加标回收试验,5种待测物的平均回收率为74.5%~114.1%。日内、日间相对标准偏差分别为1.3%~12.3%和1.3%~11.5%。将该方法用于实际水样的检测,市政污水检测出微量的酮洛芬和氟比洛芬,含量分别为14.52 ng/L和10.05 ng/L。该方法具有良好的灵敏度、准确度和精密度,操作简便,耗时短,为环境水体中痕量非甾体抗炎药富集检测提供了新方法。

Determination of seven phenoxy acid herbicides in water by dispersive solid phase extraction-ultra performance liquid chromatography-tandem mass spectrometry based on cationic metal-organic framework mixed matrix membrane

离子型金属有机骨架材料(iMOFs)对离子型化合物具有良好的选择吸附性,利用水热法合成了一种金属有机骨架材料MIL-101-NH2,以聚偏二氟乙烯(PVDF)为交联剂将其制备成混合基质膜(MMM),然后用三氟甲烷磺酸甲酯进行季胺基功能化改性,最终得到阳离子型金属有机骨架膜材料MIL-101-$NMe_{3}^{+}$-PVDF MMM,采用分散固相萃取方式富集水中的苯氧羧酸类除草剂,建立了一种基于阳离子型MOF混合基质膜的分散固相萃取-超高效液相色谱-串联质谱(UPLC-MS/MS)测定水体中7种苯氧羧酸类除草剂的分析方法。通过傅里叶变换红外光谱和扫描电子显微镜对制备的混合基质膜进行表征,结果表明季胺基功能化改性是成功的,得到了阳离子型MOF膜。对影响萃取效果的主要因素(吸附剂用量、水样pH值、萃取时间、洗脱剂种类、洗脱剂体积及洗脱时间)进行了优化,确定了最佳萃取条件。以0.01%(v/v)甲酸水溶液和乙腈作为流动相进行梯度洗脱,目标化合物在ACQUITY UPLC BEH C18色谱柱(100 mm×2.1 mm, 1.7 μm)上分离,在电喷雾电离源、负离子模式下进行多反应监测(MRM),外标法定量。结果表明,7种苯氧羧酸类除草剂在各自范围内线性关系良好,线性相关系数均大于0.997,方法的检出限(LOD)和定量限(LOQ)分别为0.00010~0.00090 μg/L和0.00033~0.00300 μg/L。在0.005、0.05和0.2 μg/L 3个加标水平下进行加标回收率试验,7种待测物的平均回收率为80%~102%,日内、日间相对标准偏差分别为1.4%~9.4%和4.2%~12.6%。该方法操作简单、快速,灵敏度高,适用于环境水体中7种苯氧羧酸类除草剂的检测。

Determination of nine ginsenosides in health foods by solid extraction phase-ultra performance liquid chromatography-tandem mass spectrometry

建立了以固相萃取结合超高效液相色谱-串联质谱(UPLC-MS/MS)同时检测保健食品中9种原人参二醇型和原人参三醇型人参皂苷的方法。保健食品中人参皂苷经过提取后,通过Alumina-N/XAD-2 SPE柱净化,在Hypersil Gold C18色谱柱(100 mm×2.1 mm, 1.9 μm)上分离,利用乙酸铵溶液(含0.1%甲酸)和乙腈作为流动相进行梯度洗脱,采用负离子扫描,多反应监测模式测定,外标法定量。研究通过对不同填料的固相萃取小柱的考察,最终选择了Alumina-N/XAD-2复合填料,其能对保健食品复杂基质中的人参皂苷进行有效富集和净化;通过考察人参皂苷的电离裂解过程,确定人参皂苷一级质谱准分子离子和相应的碎片离子,并经过色谱条件的优化,使质谱条件下一级质谱准分子离子和相应的碎片离子均一致的3种原人参二醇型人参皂苷Rb2、Rb3、Rc同分异构体实现完全分离。结果表明,9种人参皂苷在0.005~0.5 μg/mL范围内具有很好的线性关系,相关系数均大于0.9950。方法的加标回收率为81.1%~114.2%,相对标准偏差为0.4%~8.0%。所建立的方法采用XAD-2大孔吸附树脂和中性氧化铝的复合固相萃取材料,保健食品经过简单提取可直接作为固相萃取的上样溶液进行人参皂苷的富集和净化,通过超高效液相色谱-串联质谱不仅缩短了分析时间,也能对复杂基质样品中含量相对较低的人参皂苷进行准确定性和定量。该方法通量高,简单快速,重复性好,适用于保健食品中9种人参皂苷的定性和定量分析。

Determination of 18 pesticide residues in environmental water by solid phase extraction-ultra performance liquid chromatography-tandem mass spectrometry

A method was developed for the simultaneous determination of 18 pesticide residues in environmental water by solid phase extraction-ultra performance liquid chromatography-tandem mass spectrometry (SPE-UPLC-MS/MS). The samples were purified and enriched by a large-volume SPE apparatus through a Cleanrt®-PEP SPE column at a rate of 2 mL/min. After being concentrated 50-fold, the samples were detected by UPLC-MS/MS and quantified by the external standard method. The target compounds showed good linearity in the range of 0.5-50 μg/L, with linear correlation coefficients (R2) ≥0.995. At spiked levels of 10, 100 and 1000 ng/L, the average recoveries of the 18 pesticides in the three different environmental water samples were 71.3%-105.9%, and the relative standard deviations (RSDs, n=5) were 1.3%-9.9%. LOQs of the 18 pesticides were 10 ng/L. The method was applied to the detection of the water environment around Tai'an City, and no pesticide residues were detected at any of the collection sites. The method has the advantages of good purification effect, high versatility, sensitivity, and accuracy, and operational simplicity. The method is suitable for the determination of the 18 pesticides in environmental water.

Determination of diazepam in aquatic products by ultra performance liquid chromatography-tandem mass spectrometry with pass-through solid phase extraction

A method was developed for the determination of diazepam in aquatic products by pass-through solid phase extraction-ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The analyte was extracted with acetonitrile directly and purified on a Prime HLB solid phase extraction column (60 mg/3 mL). The separation was performed on an Acquity UPLC BEH C18 column (100 mm×2.1 mm, 1.7 μm)using methanol-0.1% (v/v) formic acid aqueous solution as the mobile phase in gradient elution mode. Qualitative analysis was performed in the multiple reaction monitoring (MRM) mode. The analyte was quantified by matrix-matched external standard curves. The results showed good linear relationship in the range of 0.1-10 ng/mL, and the correlation coefficient (r2) was greater than 0.99. The spiked recoveries of diazepam were 88.2%-101.1% at the spiked levels of 1.5, 3.0 and 15.0 μg/kg, and both the intra-and inter-day precisions were less than 10%. The developed method is simple, rapid and accurate, and it can meet the requirements for diazepam determination in aquatic product samples.

Determination of the Residue Behavior and Risk Assessment of Chlorfluazuron in Chinese Cabbage, Kale, Lettuce and Cauliflower by UPLC-MS/MS.

Chlorfluazuron is used as a highly effective insect growth regulator to control a variety of crop pests. However, residues of this pesticide have been shown to be harmful to human health. To evaluate the residual dissipation pattern and risk for dietary intake of chlorfluazuron in various vegetables, a solid phase extraction-ultra performance liquid chromatography-tandem mass spectrometry method was established to analyze chlorfluazuron residues in Chinese cabbage, Chinese kale, Chinese lettuce, and cauliflower. The sample was extracted with acetonitrile and purified using an SPE amino column. The average recovery of the target sample in the analyzed four vegetables was between 75.0% and 104.1%, and the relative standard deviation was between 2.5% and 9.6%. The precision and accuracy of the analysis met the requirements of residue analysis standards. Dissipation kinetic testing of chlorfluazuron in different vegetables showed a half-life of 2.4–12.6 days, with a rapid dissipation rate. The estimated daily intake of the chlorfluazuron was 0.753–1.661 μg/(kg bw·d), and the risk quotient was 0.15–0.35. It showed that chlorfluazuron had a low risk of chronic dietary intake from vegetables in different populations in China. The results of this study has described the degradation rate of chlorfluazuron in four vegetables, evaluated the risk of dietary exposure to Chinese residents. Therefore, it provides supporting data and empirical basis for guiding the reasonable use of chlorfluazuron in vegetable production and in evaluating its dietary intake risk in vegetables.

Occurrence and ecological risk of pharmaceuticals and personal care products (PPCPs) and pesticides in typical surface watersheds, China

To evaluate the occurrence and ecological risk of organic contaminants in aquatic environment in China, a method for simultaneously detecting 130 pharmaceuticals and personal care products (PPCPs) and 35 pesticides has been established using solid phase extraction-ultra performance liquid chromatography-tandem mass spectrometry (SPE-UPLC-MS/MS) method. In the present survey, a total of 122 target compounds (103 PPCPs and 19 pesticides) were detected in seven major watersheds in China, with average concentrations ranged from 0.02 ng/L (sulfamerazine) to 332.75 ng/L (bisphenol A), revealing that PPCPs and pesticides were widely distributed in surface water of China. Antibiotics and organophosphorus were the most ubiquitously PPCPs and pesticides, respectively; quinolones were the predominant antibiotics, most of which were detected in more than 96% sampling sites, with average concentrations ranged from 2.14 to 309.67 ng/L; six pesticides including isoprocarb, fenobucarb, acetamiprid, imidacloprid, acetochlor and bentazone were detected in more than 80% sampling sites, with average concentrations ranged from 5.62 to 225.93 ng/L; more than half of the non-antibiotic pharmaceuticals were hormones; and diethyltoluamide (DEET) was predominant personal care products; The risk assessment showed that each watershed was at potential medium ecological risk based on their mean concentration (RQTotal > 1), and pesticides were the main compounds arising risks.

Rapid determination of ultra-trace levels of atrazine in surface water by on line solid phase extraction coupled with ultra-performance liquid chromatography-tandem mass spectrometry

A method for the determination of ultra-trace atrazine in surface water was developed based on on line solid phase extraction-ultra performance liquid chromatography-tandem mass spectrometry (on line SPE-UPLC-MS/MS). The water sample was directly injected into an on line SPE system after filtering using a 0.22 μm filter membrane. An HLB Direct Connect HP column was used for the enrichment and purification of the water sample and eluted using a methanol solution. The analyte was separated on an Acquity BEH 130 column, and then detected by tandem mass spectrometry. The analyte was quantified with external standard method. There was a good linear relationship in the range of 1.0-5000 ng/L. The correlation coefficient (r) was 0.9989. The method detection limit was 0.2 ng/L. The recoveries of atrazine ranged from 83.0% to 105.1%. The relative standard deviation was 1.6%-5.3% (n=7), which met the requirements of trace analysis. The method is sensitive, fast and effective, and it is suitable for the determination of atrazine in surface water. It is important to ensure the safety of the water environment, provide timely pollution information, and effectively respond to environmental emergencies.

Method development and validation: solid Phase extraction-ultra performance liquid chromatography-tandem mass spectrometry quantification of pirlimycin in bovine feces and urine.

Pirlimycin, a lincosamide antibiotic, is one of the most commonly used antibiotics for the treatment of mastitis in dairy cows. Assessment of pirlimycin loadingto the environment via fecal and urinary excretion is critical to develop efficient management strategies to reduce environmental pollution by the livestock industry. Therefore, the aim of this study was to develop and validate an analytical method to identify and quantify pirlimycin in bovine feces and urine. Samples were extracted with methanol- phosphate buffer and cleaned up by SPE before analysis for pirlimycin using UPLC-MS/MS. This method was sensitive (LOQ 1.47 ng/g wet feces, 0.90 ng/mL urine), accurate (recovery, 80-108%), and precise (repeatability, 2.3-13%; reproducibility, 2.3-14%) for both bovine feces and urine. With the application of this method to samples collected in the first 10 h and then every 24 h for 120 h following intramammary dosing (50 mg/cow; n = 3 cows), pirlimycin was detected at 40.5-287 ng/g and 46.1-254 ng/mL in feces and urine, respectively. This robust, sensitive, and accurate method can be used to assess the fate and environmental impact of antibiotics used on farms.

Simultaneous determination of three estrogens in feed by solid phase extraction-ultra performance liquid chromatography-tandem mass spectrometry

A method was developed for the simultaneous determination of three estrogens (17β-estradiol, estradiol benzoate, estradiol valerate) in feed by solid phase extraction-ultra performance liquid chromatography-tandem mass spectrometry (SPE-UPLC-MS/MS). After the sample was extracted by acetonitrile and cleaned-up on a Heaion C18 solid phase extraction (SPE) column, the three estrogens were separated by an ACQUITY UPLC BEH C18 column (50 mm x 2.1 mm, 1.7 μm) with gradient elution using acetonitrile and 0.1% ammonia solution as mobile phases and finally confirmed and quantified in multiple reaction monitoring (MRM) mode. The internal standard calibration curves were used for the quantification. The results showed that all the estrogens were determined with excellent linear relationships from 10 μg/L to 200 μg/L for 17β-estradiol and estradiol valerate, and from 5 μg/L to 200 μg/L for estradiol benzoate. The correlation coefficients (r) of the three estrogens were not lower than 0. 996. The limits of detection for 17β-estradiol, estradiol benzoate and estradiol valerate were 7 μg/kg, 5 μg/kg and 7 μg/kg, respectively. The average recoveries were 96.5%-102.0%. The results demonstrated that the developed method can simultaneously determine the three estro- gens in feed with advantages of simple pretreatment, rapid analysis, low limit of detection and high accuracy.

Simultaneous Determination of 6 Industrial Dyes in Foods by Solid Phase Extraction-Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry

Simultaneous Determination of 6 Industrial Dyes in Foods by Solid Phase Extraction-Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry

Simultaneous Determination of Rhodamine B, Crystal Violet and Malachite in Aquatic Flavourings by Solid-phase Extraction Coupled with Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry

A method was developed for the simultaneous determination of rhodamine B,crystal violet and malachite in aquatic flavourings based on solid phase extraction-ultra performance liquid chromatography-tandem mass spectrometry.The samples were extracted with acetonitrile-buffer,partitioned against methylene dichloride and then cleaned up by a solid phase extraction cartridge.The target analytes were separated on a BEH C18 column with gradient elution using acetonitrile and water(containing 0.2%(V/V) formic acid) as mobile phases.The linear ranges were from 5×10-4 to 1 mg/L with the limits of detection of 0.18-0.48 μg/kg.The recoveries of the method were 90.7%-96.8%,78.4%-90.3%,78.6%-88.9%,respectively.