Directly‐coupled‐column ultra‐fast liquid chromatography with diode array detection method for the rapid quantification of allergenic disperse dyes in water preconcentrated by magnetic solid‐phase extraction

A directly‐coupled‐column ultra‐fast liquid chromatography coupled with diode array detection method for the determination of 12 allergenic disperse dyes in river water at sub‐ppb levels has been developed and successfully validated. The analytical method is based on the use of two different reversed‐phased columns connected through a two‐position switching valve. A baseline separation was achieved by proper selection of stationary phases, mobile phases, and the use of a gradient elution in both dimensions. Furthermore, an easy‐to‐handle magnetic solid‐phase extraction procedure was developed for the preconcentration of 12 allergenic disperse dyes from river water. An enrichment factor of 100 times was obtained. The results showed excellent performance in terms of trueness (76.8–99.0%), precision (intraday: 2.2–8.0%, interday: 3.3–8.2%), and sensitivity (limits of determination, 0.027–1.46 μg/L). Twenty real samples collected from the outfalls in the Yaojiang, Yongjiang and Fenghuajiang estuary were analyzed, and three of the studied compounds were found in one collected sample (12.6 μg/L for disperse blue 7, 11.6 μg/L for disperse blue 106, and 0.22 μg/L for disperse blue 3).     

Comparison of ultra high performance supercritical fluid chromatography,ultra high performance liquid chromatography,and gas chromatography for the separation of synthetic cathinones

A comparison of ultra high performance supercritical fluid chromatography, ultra high performance liquid chromatography, and gas chromatography for the separation of synthetic cathinones has been conducted. Nine different mixtures of bath salts were analyzed in this study. The three different chromatographic techniques were examined using a general set of controlled synthetic cathinones as well as a variety of other synthetic cathinones that exist as positional isomers. Overall 35 different synthetic cathinones were analyzed. A variety of column types and chromatographic modes were examined for developing each separation. For the ultra high performance supercritical fluid chromatography separations, analyses were performed using a series of Torus and Trefoil columns with either ammonium formate or ammonium hydroxide as additives, and methanol, ethanol or isopropanol organic solvents as modifiers. Ultra high performance liquid chromatographic separations were performed in both reversed phase and hydrophilic interaction chromatographic modes using SPP C18 and SPP HILIC columns. Gas chromatography separations were performed using an Elite‐5MS capillary column. The orthogonality of ultra high performance supercritical fluid chromatography, ultra high performance liquid chromatography, and gas chromatography was examined using principal component analysis. For the best overall separation of synthetic cathinones, the use of ultra high performance supercritical fluid chromatography in combination with gas chromatography is recommended.     

Multiconstituent identification in root,branch, and leaf extracts of Juglans mandshurica using ultra high performance liquid chromatography with quadrupole time‐of‐flight mass spectrometry

As a traditional medicinal plant, Juglans mandshurica has been used for the treatment of cancer. Different organs of this plant showed anti‐tumor activity in clinic and laboratory. Comparative identification of constituents in different plant organs is essential for investigation of the relationship between chemical constituents and pharmacological activities. For this aim, the roots, branches, and leaves of J. mandshurica were extracted with 50% v/v methanol and then subjected to ultra‐high performance liquid chromatography with quadrupole time‐of‐flight mass spectrometry analysis conducted under low and high energy. As a result, we have to date identified 111 compounds consisting of 56 tannins, 29 flavonoids, 13 organic acids, 8 naphthalene derivatives, and 5 anthracenes. Five compounds, namely, diquercetin trihydroxy‐truxinoyl‐glucoside, two quercetin kaempferol dihydroxy‐truxinoyl‐glucosides, syringoyl‐tri‐galloyl‐O‐glucose, and dihydroxy‐naphthalene syringoyl‐glucoside, were tentatively identified as new compounds. Of the compounds identified, 76 were found in the root extract, 67 in the branch extract, and 37 in the leaf extract. Only six compounds including four organic acids and two tannins were found in all three extracts. We developed a rapid and sensitive ultra high performance liquid chromatography with quadrupole time‐of‐flight mass spectrometry approach to identify multiple constituents of complex extracts without separation and ion selection. The results presented provide useful information on further research of the bioactive compounds of J. mandshurica .     

芥子气中毒人员尿液标记物谱分析及其临床诊断应用

该研究基于暴露生物标记物溯源思路,应用于解决芥子气(SM)临床早期诊断、溯源确证难题。建立了芥子气中毒患者尿液中7种游离代谢产物的两步固相萃取/超高效液相色谱-串联质谱(SPE/UPLC-MS/MS)同时定量方法,检出限为5 pg/mL~1 ng/mL,定量下限为10pg/mL~5 ng/mL;结合前期建立的4种游离碱基加合物的同位素稀释-UPLC-MS/MS定量方法,对1例疑似芥子气中毒人员尿液中可能赋存的生物标记物进行了全筛查分析。尿液中共检出3类10种生物标记物,包括首次报道的游离代谢产物芥子亚砜,可确证患者为芥子气中毒;除硫二甘醇外,标记物含量均在暴露后3~4 d达到峰值,随后降低,至7 d仍可检出,其中谷胱甘肽加合物的β裂解产物含量相对较高,可作为芥子气中毒早期诊断与疗效评估的重要指标。     

基于非靶向代谢组学的茄梨和红茄梨成熟期果皮代谢产物的差异分析

为了探究西洋梨品种茄梨及其红色芽变红茄梨成熟期果皮代谢产物差异,采用超高效液相色谱-质谱联用技术,对茄梨和红茄梨成熟期果皮进行非靶向代谢组学研究。通过主成分分析和正交偏最小二乘判别分析,构建了多变量统计分析模型,结合模型和变量重要性投影与最大差异倍数值,基于精确质量数、二级碎片以及同位素分布,使用PMDB(Plant Metabolome Database)数据库进行定性,筛选并鉴定出茄梨和红茄梨果皮中显著性变化(P<0.05, VIP(variable importance in project)≥1)的差异代谢物有83种,主要包括酚酸类、黄酮类和氨基酸类物质,涉及类黄酮代谢、氨基酸代谢、苯丙烷类代谢等代谢途径,其中53种物质含量上调,30种物质表达下调。通过KEGG(Kyoto Encyclopedia of Genes and Genomes)数据库进一步对差异代谢物质进行通路富集分析,差异代谢物主要分布在20条代谢途径中,P<0.05的代谢途径有6条,分别是类黄酮生物合成、黄酮和黄酮醇生物合成、苯丙烷生物合成、丁酸酯代谢、苯丙氨酸代谢、酪氨酸代谢。这些差异代谢物的变化可能是导致茄梨和红茄梨果皮色泽不同的原因。该研究从植物代谢组学角度初步揭示了茄梨和红茄梨成熟期果皮的代谢产物差异性。     

柱前衍生-超高效液相色谱法测定3种奶粉中18种氨基酸

近年来羊奶粉和骆驼奶粉备受消费者青睐,它们具有潜在的低致敏性,因此成为牛乳不耐受人群尤其是婴幼儿的母乳替代品,其营养价值备受关注。牛奶粉、羊奶粉和骆驼奶粉中氨基酸含量的比较研究鲜有报道。利用酸水解得到游离氨基酸,选择6-氨基喹啉-N-羟基琥珀酰亚胺氨基甲酸酯(AQC)进行柱前衍生,超高效液相色谱分离并检测,外标法定量。18种氨基酸在各自线性范围内线性关系良好,相关系数(r ²)大于0.999;以3倍和10倍信噪比(S/N)确定方法的检出限(LOD)和定量限(LOQ),分别为1.3~2.5 (mg/100 g)和3.9~7.5 (mg/100 g)。方法验证采用奶粉标准参考物质SRM 1849a,测定值符合其含量范围,6次测定值的相对标准偏差(RSD)为2.04%~3.65%。采用建立的方法分别对市售和网购的牛奶粉、羊奶粉和骆驼奶粉进行18种氨基酸成分和含量分析,旨在从氨基酸角度对这3种不同来源乳品进行对比。该方法快速,灵敏度高,准确可靠,适用于不同基质乳粉中18种氨基酸成分和含量的确定。     

超高效液相色谱-串联质谱法定量分析尿液中色氨酸及其代谢产物

基于超高效液相色谱-串联质谱(UPLC-MS/MS)建立定量分析色氨酸(Trp)及代谢产物3-OH-犬尿氨酸(3-OH-Kyn)、3-OH-邻氨基苯甲酸(3-OH-AA)、黄尿酸(XA)、犬尿氨酸(Kyn)、5-羟基吲哚乙酸(5-HIAA)、犬尿喹啉酸(KA)和5-羟色胺(5-HT)的方法,应用该方法分析其在尿样中的含量,探讨排泄规律。将尿样稀释、离心后,加入丹磺酰氯(DNS-Cl)衍生,经Thermo C₁₈色谱柱(50 mm×3 mm, 2.7 μm)分离和0.1%甲酸和甲醇梯度洗脱后,采用电喷雾电离(ESI)源,在正离子扫描和多反应监测(MRM)模式下检测。以咖啡酸(CA)为内标,定量分析。结果显示,8种目标化合物的线性关系良好,相关系数(R ²)≥0.9740,检测灵敏(LOD为0.005~0.5 ng/mL),回收率高(93.24%~107.65%)。采用本方法检测分析了健康志愿者70个尿液样本,在尿样中检测到Trp原型及其7种代谢产物。结果表明,体内的Trp是通过原型和代谢两种方式排泄:Trp原型的含量为5.22~20.88 μg/mL;尿液中经代谢后排泄的Trp量是原型的124%~268%,即体内的Trp主要经代谢后排出体外。方法主要研究了Trp-5-HT和Trp-Kyn两条途径的代谢产物含量,Trp经Kyn降解生成的3-OH-AA和3-OH-Kyn含量较多,即Trp-Kyn是体内Trp的主要代谢途径。方法通过UPLC-MS/MS实现了尿液中Trp及其代谢产物含量的检测,能为临床检查提供技术和理论支持。     

Double-ion imprinted polymer @magnetic nanoparticles modified screen printed carbon electrode for simultaneous analysis of cerium and gadolinium ions

A typical, reproducible, and rugged screen printed carbon electrode, modified with dual-ion imprinted beads, was fabricated employing the “surface grafting from” approach. For this, the acyl chloride functionalized magnetic nanoparticles were first immobilized and chemically attached with a typical functional monomer (but-2-enedioic acid bis-[(2-amino-ethyl)-amide]) on the electrode surface. This was subsequently subjected to the thermal polymerization in the presence of template ions (Ce(IV) and Gd(III)), cross-linker (ethylene glycol dimethacrylate), initiator (AIBN), and multiwalled carbon nanotubes. The modified sensor was used for the simultaneous analysis of both template ions in aqueous, blood serum, and waste-water samples, using differential pulse anodic stripping voltammetry which revealed two oxidation peaks for respective templates with resolution as much as 950 mV, without any cross reactivity, interferences and false-positives. The detection limits realized by the proposed sensor, under optimized conditions, were found to be as low as 0.07 ng mL⁻¹ for Ce(IV) and 0.19 ng mL⁻¹ for Gd(III) (S/N = 3) that could eventually be helpful for lanthanide estimation at stringent levels.     

超高效液相色谱-四极杆-飞行时间质谱同时筛查腐败血液中24种农药

利用超高效液相色谱-四极杆-飞行时间质谱(UPLC-Q-TOF-MS)技术建立了腐败血液中24种常见投毒农药的快速筛查方法。采用Qu ECh ERS方法进行样品前处理。腐败血液经乙腈-水(4∶1)提取,同时加入无水硫酸镁脱水,超声后过0.22μm滤膜后直接测定。目标药物经ACQUITY UPLCTMHSS C18柱分离,以乙腈和0.1%甲酸-甲酸铵水溶液为流动相进行梯度洗脱,采用正离子全信息串联质谱扫描模式(MSE)进行筛查。结果表明,腐败血液中24种农药的检出限(LOD,S/N=3)为0.43~10.0 ng/m L;3个加标水平下的平均回收率为61%~98%,相对标准偏差(RSD)为1.5%~16.9%。该方法快速简便、灵敏度较高,可用于腐败血液中24种常见投毒农药的快速筛查。     

Comparative analysis of the main active components and hypoglycemic effects after the compatibility of Scutellariae Radix and Coptidis Rhizoma

In this study, a rapid and highly sensitive ultra high performance liquid chromatography with triple quadrupole mass spectrometry method with the mobile phase of acetonitrile and 0.1% aqueous formic acid was established and successfully applied to comparatively analyze main active components after their compatibility. Besides, the effects of Scutellariae Radix, Coptidis Rhizoma and combined extracts on type 2 diabetic rats induced by high‐fat diet along with low dose of streptozocin were investigated. Under the optimized chromatographic conditions, good separation of seven target components was achieved within 12 min. All calibration curves exhibited good linearity (R² ≥ 0.999). The relative standard deviation of precision, repeatability and stability varied from 0.69 to 2.23, 0.98 to 2.56, and 0.92 to 2.57%, respectively. The recovery ranged from 91.11 to 105.35%. The contents of seven active components were notably reduced after compatibility; however, the hypoglycemic effect of combined extracts was stronger than single drug by decreasing the activities of fructose‐1,6‐bisphosphatase, glucose 6‐phosphatase, phosphoenolpyruvate carboxykinase and increasing the activities of glucokinase, phosphofructokinase, pyruvate kinase. Accordingly, the established analytical method was accurate and sensitive enough for quantitative evaluation of seven investigated compounds. Moreover, the combined extract had definite effects on type 2 diabetes through multiple components against multiple targets.