Simultaneous Determination of Preservatives,Artificial Sweeteners,and Synthetic Dyes in Kimchi by Ultra-Performance Liquid Chromatography Electrospray Ionization Tandem Mass Spectrometry (UPLC-ESI-MS/MS)

Abstract

A simple and rapid method was developed for the simultaneous determination of five preservatives, six artificial sweeteners, and nine synthetic dyes in kimchi using ultra-performance liquid chromatography electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS) with multiple reaction monitoring (MRM). The chromatographic separation was performed in 5.5?min using an Acquity UPLC BEH C18 column (100?mm × 2.1?mm, 1.7?µm) with a mobile phase composed of 0.002% trifluoroacetic acid and 10?mM aqueous ammonium acetate or 9:1 (v/v) methanol:acetonitrile. Linear calibration curves were obtained with correlation coefficients above 0.98. The limits of quantification ranged between 0.227 and 8.569?ng/mL, while the recovery values in kimchi samples were from 83.1 to 113.5%. Forty kimchi samples were analyzed for the food additives, with sweeteners detected in more than half of these samples. The most commonly detected sweetener was saccharin, and six of the kimchi samples contained a combination of sweeteners; dulcin, sucralose, acesulfame K, preservatives, and synthetic dyes were not detected. Based on these results, the developed method can be used for the rapid quality control of food additives in kimchi.     

杜仲中京尼平甙酸的硅胶柱色谱分离纯化及反相高效液相色谱/液相色谱-电喷雾质谱/核磁共振鉴定

建立了杜仲中京尼平甙酸的硅胶柱色谱分离纯化及反相高效液相色谱/液相色谱-电喷雾质谱/核磁共振(RP-HPLC/LC-ESI-MS/NMR)鉴定方法。杜仲皮经粉碎后,用70%乙醇提取,提取液经减压蒸馏至干,再用甲醇溶解,然后吸附于硅胶上,并以不同体积比的氯仿-甲醇混合液按洗脱剂的极性由小到大进行洗脱,以RP-HPLC法检测洗脱液中物质的种类和含量。结果表明:洗脱剂为氯仿-甲醇（体积比为8∶1）的洗脱液经分析为单一组分,其保留时间为5.142 min;以对照品京尼平甙酸添加法测定,其峰高增加;相关紫外光谱和红外光谱检测结果与京尼平甙酸对照品基本一致;结合LC-ESI-MS、 1H-NMR和13C-NMR等测定,确定该洗脱组分为京尼平甙酸。     

核磁共振氢谱内标法测定茚地普隆的含量

建立了测定无对照品的新型非苯二氮唑类镇静催眠药茚地普隆含量的快速、专属、简单的核磁共振氢谱内标法。用Varian Mercury Plus400MHz核磁共振谱仪,在25℃、以氘代氯仿为溶剂、3,4-二硝基甲苯为内标、观察频率400.121MHz、谱宽6410Hz、90°脉冲宽度6.45μs、采集时间4s和延迟时间15s的条件下采集试样的氢谱。以化学位移分别在δ8.72和δ8.72处的茚地普隆和3,4-二硝基甲苯的单峰作为定量峰,其峰面积比(As/Ar,y)与其质量比(ms/mr,x)的线性回归方程为y=6.1458x 0.0055,相关系数为r=0.99996,含量测定重复性实验的RSD为0.29%(n=6)。分析结果表明,在没有对照品的情况下,核磁共振氢谱内标法,可用于茚地普隆的含量测定和质量控制。     

高效液相色谱－核磁共振联用技术及其应用

高效液相色谱－核磁共振（ＨＰＬＣ－ＮＭＲ）在线联用技术是同时进行未知混合物的分离和结构鉴定的最好手段之一。详细介绍了在ＨＰＬＣ－ＮＭＲ联用技术中１Ｈ谱的分辨率、检测限和多重溶剂峰抑制的最新进展，并简要评述了其它分离方法与ＮＭＲ联用情况     

高效液相色谱－核磁共振联用技术及其应用

高效液相色谱－核共共振在线联用技术是同时进行未知混合物的分离和结构鉴定的量好手段之一。详细介绍了在ＨＰＬＣ－ＮＭＲ联用技术中Ｈ谱的分辨率，检测限手多重溶剂峰抑制的最新进展，并简要评述了其它分离方法与ＮＭＲ联用情况。     

高效液相色谱-核磁共振仪联用技术在耐哌地尔杂质检测中的应用

用高效液相色谱-核磁共振（HPLC-CNM）联用技术中的连续流动和停止流动两种模式对萘哌地尔中杂质进行检测,根据^1HNMR,^1H-^1HCOSY谱完成了主要杂质1-萘环-丙三醇结构鉴定。HPLC-NMR是解决合成药物中杂质结构确证的简便、快速方法。     

Characterization of 8-Deuterium Substituted Proton Pump Inhibitors by Nuclear Magnetic Resonance and Electrospray Ionization Mass Spectrometry

Nuclear magnetic resonance (NMR) was employed to characterize the hydrogen-deuterium exchange for the proton pump inhibitors pantoprazole sodium, esomeprazole sodium, rabeprazole sodium, lansoprazole, and ilaprazole in methanol-d₄. The results showed that the ¹H and ¹³C signals of 8-CH₂ (labeled as H_8a, H_8b, and C₈) next to the sulfinyl (S?O) group of the proton pump inhibitors decreased significantly. Electrospray ionization mass spectrometry showed the presence of deuterated products. Basing on the NMR data, H_8a and H_8b of proton pump inhibitors were more active for the hydrogen-deuterium exchange. The most significant parameter governing the exchange was the salt-formation of the benzimidazole group. Therefore, the influence of salt-formation on hydrogen-deuterium exchange was characterized for ilaprazole; replacement of NH by N–Na on the benzimidazole group accelerated the exchange process. Tandem mass spectrometry showed that CH?S–OH was formed by tautomerism involving sulfinyl and CH₂ groups in methanol-d_4.     

核磁共振波谱法测定液体乳中的1,2-丙二醇

采用核磁共振氢谱(¹H NMR)、选择性一维全相关谱(1D-TOCSY)及定量核磁共振法(qNMR)对液态乳中的1,2-丙二醇进行了快速筛查及含量测定,并与气相色谱法的测定结果进行了比较。¹H NMR法以液态乳基质中1,2-丙二醇的甲基质子信号特征为初步定性标准,选择性一维全相关谱法以1,2-丙二醇的亚甲基和次甲基质子信号特征为精确定性标准。在定性检测基础上,采用定量核磁共振法以1,2-丙二醇δ 1.15处的质子峰为定量峰,3-(三甲基硅基)氘代丙酸钠(TMSP)δ 0.00处的峰为内标峰,测定了液体乳中1,2-丙二醇的绝对含量。方法的检出限为0.002 mg/mL,定量下限为0.006 mg/mL。实际样品测定结果显示,NMR法与气相色谱法的检测结果一致,且NMR法前处理简单,操作方便,专属性高,在提高检测效率的同时能够避免假阳性结果出现,非常适合实际检测中液体乳中1,2-丙二醇的批量、快速检测。     

高效液相色谱串联质谱法测定牛奶中的高氯酸盐

建立了高效液相色谱-串联质谱测定牛奶中高氯酸盐的方法.样品经1%乙酸-乙腈(体积比1:4)混合溶液提取,于6 000 r/min离心20 min后,经0.2μ m的尼龙滤膜、On-GuardⅡRP柱、On-GuardⅡAg柱和On-GuardⅡBa柱净化,最大反相性能色谱柱C12(Synergi 4u MAX-RP 8...     

基于HPLC-MS技术的黄颡鱼中不同部位脂质成分分析

利用超高效液相色谱-飞行时间质谱技术(UPLC-Q-TOF-MS/MS)分析了黄颡鱼不同部位的脂质成分。采用甲醇-氯仿(1∶1,体积比)对血清、肌肉和肝脏进行脂质成分提取。液相色谱采用C8色谱柱,柱温40℃,流动相A为乙腈-甲醇-异丙醇(1∶1∶1),流动相B为乙腈-水(0.1%甲酸,0.01%氯化锂)。根据高分辨质谱获得精确分子量,推测出元素组成,并结合脂质成分的二级质谱裂解规律,在血清、肌肉和肝脏中共鉴定出85个脂质成分,主要有PC,Lyso-PC,PE,Lyso-PE,PI,PS,DAG,TAG,SM和Cer。在这3个部位中有19个共有脂质成分,包括Lyso-PC 16∶0,9个PC,3个PI,4个TAG和2个SM。此外PS和Lyso-PE仅在肌肉中鉴定出,分别为PS 18∶0/22∶6,Lyso-PE 16∶0和Lyso-PE 18∶1;神经酰胺仅在肝脏中观察到,为Cer(d18∶1/24∶1);而PE和DAG只在肌肉和肝脏中存在,在血清中未发现。该方法操作简单、灵敏、高效,为快速、全面了解黄颡鱼中的脂质分布提供了科学依据。     

高效液相色谱-串联质谱法测定动物组织中的16种喹诺酮类药物残留

建立了动物组织样品中萘啶酸、恶喹酸、氟甲喹、诺氟沙星、依诺沙星、环丙沙星、洛美沙星、丹诺沙星、恩诺沙星、氧氟沙星、沙拉沙星、二氟沙星、麻保沙星、培氟沙星、司帕沙星、奥比沙星等16种喹诺酮类兽药多残留量的高效液相色谱-串联质谱测定方法。用酸性乙腈萃取样品中的16种喹诺酮类药物残留,然后用正己烷脱脂,旋转蒸发浓缩,以Inertsil C8-3色谱柱分离,在正离子模式下以电喷雾电离串联质谱进行测定。在10,50,100 μg/kg 3个加标水平下进行了验证试验,方法的线性范围为10~100 μg/kg,平均回收率为62.4%~102%,相对标准偏差为1.4%~11.9%。该方法简便、快速、准确,各项技术指标满足国内外法规的要求,可用于鸡肉、鸡肝和鱼肉等动物组织样品中喹诺酮类药物多残留的确证检测。     

Quality Control of Krill Oil by Nuclear Magnetic Resonance (NMR) Spectroscopy: Composition and Detection of Foreign Species

Krill oil is currently among the most highly promoted products in the dietary supplement market, which, due to its high price, can be potentially adulterated with fish species and artificial oil. For a holistic control of krill oil quality, ¹H, ¹³C, and ³¹P nuclear magnetic resonance (NMR) spectroscopies were used. The fatty acid and phospholipid composition as well as secondary ingredients, such as homarine, amino acids, and chitin, were examined. The following phospholipid species were detected: phosphatidylcholine (75–85?mol %), phosphatidylethanolamine (4–7?mol%) and their lyso derivatives 1-lysophosphatidylcholine (1–2?mol%)–2-lysophosphatidylcholine (10–16?mol%) and lysophosphatidylethanolamine (1?mol%). In the -2 position of phospholipids, the content of eicosapentaenoic acid (mean 68.23%; relative standard deviation 2.23%) was twice as high as the content of docosahexaenoic acid (mean 31.77%; relative standard deviation 4.79%). ¹³C NMR spectroscopy was used to distinguish between krill and fish oil-based dietary supplements. The adulteration of krill oil can be detected by fatty acid distribution in the sn-2 triacylglycerol position. The sensitivity of the method is about 10% (w/w) of fish content in blends, which is enough to detect deliberate adulteration. The same methodology can be used to recognize synthetically modified krill oil. The method was successfully applied to 30 commercially available krill and fish oil supplements.     

超高效液相色谱串联质谱法测定花生、粮油中18种真菌毒素

采用同位素稀释法并结合凝胶色谱净化技术,建立了花生、粮油中18种常见真菌毒素污染的超高效液相色谱串联质谱分析方法.样品中添加同位素内标U-[13C17]-黄曲霉毒素 B1和U-[13C15]-脱氧雪腐镰刀菌烯醇,经乙腈-水溶液(84:16,体积比)均质提取,凝胶渗透色谱净化,Waters ACQUITY UPLCTM ...     

液相色谱-串联质谱法同时测定血浆中白藜芦醇苷及其代谢产物

建立同时测定大鼠血浆中白藜芦醇苷及其代谢产物白藜芦醇的液相色谱-串联质谱方法。以Lichro-spher C18色谱柱为分析柱,乙腈-水为流动相,采用电喷雾离子源(ESI),以多反应监测(MRM)模式检测,内标法定量,用于定量分析的离子反应分别为m/z389/227(白藜芦醇苷)和m/z227/143(白藜芦醇)。血浆中的白藜芦醇苷及白藜芦醇用乙酸乙酯提取,N2吹干乙酸乙酯,残留物用甲醇溶解,注入LC/MS/MS系统进行检测。在选定的样品预处理、色谱及质谱条件下,白藜芦醇苷、白藜芦醇及内标物能够达到基线分离而且离子化效果好。用LC/MS/MS法检测大鼠血浆中的白藜芦醇苷及其代谢产物白藜芦醇,线性范围0.4~200μg/L,日内、日间精密度(RSD)均小于15%;检测血浆低、中、高3个浓度(1、20、100μg/L)白藜芦醇苷的回收率分别为106.2%、97.8%和91.6%;检测血浆低、中、高3个浓度(1、20、100μg/L)白藜芦醇的回收率分别为113.2%、103.6%和93.4%。本方法具有灵敏、准确、快速的特点,可用于白藜芦醇苷的药代动力学研究。     

液相色谱-串联质谱法测定21种植物源性食品中茚虫威残留

建立了玉米、花生、核桃、大豆油、绿茶、葡萄、韭菜、香菇以及花椒等21种植物源性食品中茚虫威残留的液相色谱-串联质谱检测方法。样品经乙腈(植物油经正己烷-乙腈)提取,谷物、油料、坚果和植物油采用凝胶渗透色谱(GPC)净化,茶叶采用固相萃取(SPE)净化,水果、蔬菜、食用菌和香辛料采用N-丙基乙二胺(PSA)、十八烷基键合硅胶(C18)、石墨化碳黑(GCB)分散固相萃取剂(d SPE)净化,C18色谱柱分离,0.1%甲酸-乙腈(30∶70)作为流动相进行等度洗脱,质谱采用电喷雾正离子(ESI+)模式电离,多离子监测模式(MRM)定性,基质标准曲线外标法定量。茚虫威的响应值与其浓度呈良好的线性关系,相关系数(r2)大于0.993。在3个加标浓度下,茚虫威的平均回收率为73.7%~115.2%,相对标准偏差不大于13.1%,方法的定量下限为1.5~9.5μg/kg,该方法可满足茚虫威残留分析的要求。     

高效液相色谱-串联质谱法同时测定食醋中4-甲基咪唑和2-乙酰基-4-(1,2,3,4-四羟基丁基)咪唑

建立了高效液相色谱-串联质谱法同时检测食醋中4-甲基咪唑(4-Methylimidazole,4-MEI)和2-乙酰基-4-(1,2,3,4-四羟基丁基)咪唑(2-Acetyl-4-(1,2,3,4-tetrahydroxybutyl)imidazole,THI)的方法。样品经超纯水稀释,用氨水溶液调节pH=9.0,采用0.22μm水系微孔滤膜过滤,以乙腈和0.05%氨水为流动相,流速为0.4mL/min,用反相色谱柱Polaris C18-A(150×4.6 mm,3μm)进行分离,采用电喷雾正离子(ESI+)模式电离,多反应监测(MRM)模式检测,以d6-4-甲基咪唑(d6-4-methylimidazole,d6-4-MEI)作为内标进行定量。4-MEI和THI在0.01~1.0mg/L之间线性关系良好(r0.9996),4-MEI和THI在所有醋中0.2mg/L、0.5mg/L和2.0mg/L三个添加浓度的回收率范围为80.2%~101.4%,相对标准偏差均小于6.4%,浅色的白醋和米醋的检出限为0.06 mg/L,定量限为0.2 mg/L;深色的香醋和陈醋的检出限为0.15mg/L,定量限为0.5mg/L。     

Determination of Anthocyanins and Flavonols in Paeonia delavayi by High-Performance Liquid Chromatography with Diode Array and Mass Spectrometric Detection

The colors of the leaves in Paeonia delavayi may be pure green, green-red, or dark red according to their habitat. The goal of this study was to compare the type and the total concentrations of anthocyanins and flavonols in red and green P. delavayi. The constituents and concentration of anthocyanins and flavonols were identified and determined by high-performance liquid chromatography with diode array detection and mass spectrometry. Cyanidin-3, 5-di-O-glucoside, cyanidin-3-O-glucoside, and peonidin-3-O-glucoside were first determined in red P. delavayi. There were no anthocyanins in green P. delavayi. Seven flavonols were identified in both red and green P. delavayi with differences in their concentrations. The concentrations of total anthocyanins and flavonoids were determined at 525 and 360?nm using the external standard method. The total anthocyanins in red P. delavayi were 152.24?mg/100?g in leaves and 78.92?mg/100?g in stems. The total flavonoids were 805.4?mg/100?g in leaves and 438.3?mg/100?g in stems, which were much higher than in green P. delavayi for both leaves and stems. This study reports composition and concentration differences in red and green P. delavayi based on ecological habitat.     

高效液相色谱-串联质谱法检测食品中的草甘膦及其主要代谢物氨甲基膦酸残留

建立了高效液相色谱-串联质谱测定植物产品(大豆、大米、小麦、蔬菜、水果、茶叶等)、动物肉类产品、水产品、板栗、蜂蜜等产品中草甘膦(PMG)及其主要代谢物氨甲基膦酸(AMPA)残留量的方法。样品经水提取后用二氯甲烷除去其中的脂肪,再经阳离子交换柱(CAX)净化,用 9-芴基甲基氯仿(FMOC-Cl)衍生化,采用多反应监测技术所确定的定性离子对其进行定性,同位素内标法定量。方法的定量检测低限为0.05 mg/kg,线性范围为0.20～10 μg/L,各种基质下PMG和AMPA的平均加标回收率为80.0%～104%,相对标准偏差为6.7%～18.2%。     

液相色谱-串联质谱法测定小型家用电器塑料部件中全氟辛酸

建立了高效液相色谱-串联质谱(HPLC-MS/MS)结合加速溶剂萃取测定小型家用电器塑料部件中全氟辛酸(PFOA)的分析方法。样品冷冻粉碎后采用甲醇作溶剂进行快速溶剂萃取,萃取液经C18固相萃取柱富集净化后,以C18柱为分离柱,以甲醇-水为流动相,梯度洗脱,电喷雾负离子模式下多反应监测(MRM))模式检测。PFOA在0.5～100.0μg/L范围内线性关系良好(r2=0.998 9),回收率为93%～107%,相对标准偏差为2.9%～7.6%,检出限(S/N=3)为0.5μg/kg。该方法操作简便、灵敏度高,适用于小型家用电器塑料部件中全氟辛酸残留分析。