Determination of Selenium Species in Cordyceps militaris by High-performance Liquid Chromatography Coupled to Hydride Generation Atomic Fluorescence Spectrometry

The purpose of this work is to develop a high-efficiency extraction method for determining the selenium species in Cordyceps militaris. Six extraction solutions, including hot water, HCl, methanol–water, ammonium acetate, protease XIV, and protease K, combined with ultrasound-assisted extraction, were utilized in the measurements. The selenium species in the extracts were separated and characterized by high-performance liquid chromatography. Their concentrations were subsequently determined by hydride generation atomic fluorescence spectrometry. The 25?mM ammonium acetate was selected as the extraction solution due to its advantages in cost and efficiency. Validation was performed, and the selenium species recoveries were 69–97% for selenocystine, selenite, selenomethionine, and selenate with good linearity and precision. The major selenium species in C. militaris were selenocystine and selenomethionine that accounted for almost 73.1?±?1.6% of the total selenium.     

Speciation of Arsenic in Rice by Ion Chromatography with Online Anion Suppression and Inductively Coupled Plasma Mass Spectrometry

Arsenic speciation in rice has received attention due to its impact on food safety and human health. In this study, a sensitive method was developed for the determination of inorganic arsenic in rice using online anion suppression with ion chromatography and inductively coupled plasma mass spectrometry. HCl of 0.01?mol/L was the optimal extracting agent, and 38?mmol/L sodium carbonate and 15?mmol/L sodium acetate were used as the mobile phase to separate dimethylarsinic acid (DMA), arsenite, monomethylarsonic acid (MMA), and arsenate. The results showed that there were no significant losses or transformations with the anion suppressor and an improvement in sensitivity. The limits of quantification were 0.1?µg/L for DMA, As(III) and MMA, and 0.2?µg/L for As(V). The procedure was used to determine inorganic arsenic in rice; As(III) and DMA were the primary forms present. The reproducibility from seven measurements showed that the relative standard deviation was less than 1.68%. The recoveries were from 99.76 to 110.42%. The present work offers a new approach for the determination of inorganic arsenic in rice.     

高效液相色谱与电感耦合等离子体质谱联用技术用于胁迫富硒海带硒形态研究

通过对海带胁迫富硒培养, 研究了海带对硒的富集总量及硒化学形态转变. 建立了反相离子对缓冲盐等3个色谱系统的高效液相色谱与电感耦合等离子体质谱联用(RP-HPLC-ICP-MS)技术测定亚硒酸钠、硒甲基半胱氨酸(MeSeCys)、硒代蛋氨酸(SeMet)三种硒形态. 采用3种提取溶剂, 超声提取缩短提取时间, 分离检测富硒海带的主要硒形态为亚硒酸钠、硒甲基半胱氨酸和硒代蛋氨酸.     

固相萃取–高效液相色谱法测定豆芽中4-氯苯氧乙酸钠和6-苄基腺嘌呤的残留量

建立了测定豆芽中4-氯苯氧乙酸钠和6-苄基腺嘌呤的固相萃取–高效液相色谱法。样品以0.1 mol/L的盐酸溶液为提取剂,经C18固相萃取柱净化处理,以乙腈–10 mmol/L乙酸铵水溶液(体积比25∶75)为流动相,Tech Mate C_(18)–ST色谱柱分离,4-氯苯氧乙酸钠和6-苄基腺嘌呤的紫外检测波长分别为228 nm和267 nm,色谱峰面积外标法定量。在0.50~100.00 mg/L浓度范围内,4-氯苯氧乙酸钠的相关系数为0.999 8,精密度在1.3%~8.2%之间(n=6),回收率在103.1%~109.0%之间;在0.05~10 mg/L浓度范围内,6-苄基腺嘌呤相关系数为0.999 9,精密度在0.9%~3.8%之间(n=6),回收率在88.0%~95.4%之间。4-氯苯氧乙酸钠和6-苄基腺嘌呤的检出限(S/N=3)分别为0.24,0.02 mg/kg。该法可以同时完成豆芽中4-氯苯氧乙酸钠和6-苄基腺嘌呤的分析检测。     

同位素内标-多反应监测同步在线质谱全扫描确证火锅料中罂粟壳成分

建立了高效液相色谱-三重四极杆线性离子阱质谱测定火锅料中吗啡、可待因、蒂巴因、罂粟碱、那可丁等5种生物碱残留的确证方法。样品采用稀盐酸加热提取,正己烷除脂,阳离子混合机理固相萃取柱净化,5%氨化乙酸乙酯-甲醇洗脱,PAK ST色谱柱分离,5 mmol/L乙酸铵甲醇溶液-10 mmol/L乙酸铵水溶液(pH 3.6)作为流动相洗脱,电喷雾正离子模式下多反应监测同步增强子离子在线全扫描(EPI)。在该实验条件下,5种生物碱的LOD在0.05~0.5 μg/kg之间,增强型子离子全扫描水平限和LOQ在0.2~2 μg/kg之间,方法回收率为64.2%~110.6%, RSD为4.2%~12.5%。阳性样品的定性确证需采用其子离子全扫描质谱图与标准图库中子离子质谱图检索匹配。经测定多种火锅料,表明本方法操作简单、测定结果准确,可用于火锅料中5种生物碱残留的阳性结果确证分析。     

柱前衍生-超高效液相色谱法测定鱼卵中的17种氨基酸

建立了一种快速、灵敏的柱前衍生-超高效液相色谱-光电二极管阵列检测器(UPLC-PDA)测定史氏鲟(Acipenser schrenckii)、达氏鳇(Huso dauricus)和小体鲟(Acipenser ruthenus)鱼卵中17种氨基酸含量的方法。采用6.0 mol/L的盐酸水解鱼卵,提取液经低压浓缩、碱性中和,然后以6-氨基喹啉-N-羟基琥珀酰亚胺基氨基甲酸酯(AQC)为衍生试剂在pH 8.8硼酸盐缓冲溶液中衍生化。采用的色谱分离柱为Waters BEH C18柱(100 mm×2.1 mm, 1.7 μm),流动相为30 mmol/L乙酸铵水溶液(pH 3.5)和乙腈(含0.15%(v/v)甲酸及30 mmol/L乙酸铵),梯度洗脱,流速为0.7 mL/min,在260 nm波长下检测。17种氨基酸在5.0～1000 μmol/L浓度范围内,峰面积与浓度之间的线性关系良好(r2≥0.9950)。以标准加入法测定回收率和相对标准偏差(RSD),在100、500、750 μmol/L的添加水平下,17种氨基酸的平均回收率为75.4%～107.3%, RSD为2.19%～12.3%。以3倍信噪比(S/N＞3)计方法的检出限,17种氨基酸的检出限为0.94～4.04 μmol/L。应用该方法检测了3种鲟鳇鱼鱼卵中的17种氨基酸含量。结果表明,该方法简便、准确、快速、可靠。     

超高效液相色谱-四极杆/静电场轨道阱高分辨质谱法测定焙烤食品及其原料中11种真菌毒素

建立了超高效液相色谱-四极杆/静电场轨道阱高分辨质谱(UPLC-HRMS)测定焙烤食品及其原料中11种真菌毒素的检测分析方法。样品经20 mL含1%(体积分数)甲酸的乙腈-水(9∶1,v/v)溶液提取,经2.0 g无水硫酸、0.5 g氯化钠和300 mg C18盐析、净化后进行检测。采用CORTECS C18色谱柱(100 mm×2.1 mm,1.6μm),以含0.1%(体积分数)甲酸的2 mmol/L乙酸铵溶液和含0.1%(体积分数)甲酸的2 mmol/L乙酸铵甲醇溶液为流动相进行梯度洗脱。结果显示,11种真菌毒素在各自的质量浓度范围内线性关系良好(相关系数r2≥0.996 0),方法的定量限为0.15~20.00μg/kg,样品加标回收率为64.38%~122.61%,相对标准偏差为1.52%~12.99%(n=6)。该方法简单快速、灵敏度高、结果准确、可靠,利用该方法可有效测定焙烤食品及其原料中常见真菌毒素的含量。     

A Simple and Sensitive LC–MS/MS Method for Simultaneous Determination of Temsirolimus and Its Major Metabolite in Human Whole Blood

A simple, fast and sensitive LC–MS/MS method was developed and validated for the simultaneous determination of the concentrations of temsirolimus and its major metabolite, sirolimus, in human whole blood. The blood sample (100 μL) after adding temsirolimus-d7 and sirolimus-d3 internal standards was precipitated with 0.200 mL of methanol/0.300 M zinc sulfate (70/30, v/v), then analyzed by a Shimatzu LC system coupled to a Sciex API-5000 mass spectrometer. The chromatographic separation was carried out on a BDS Hypersil C8 column (50 × 3.0 mm, 5 μm) at 50 °C with a mobile phase composed of methanol/water/formic acid (72/28/0.1) (v/v/v) containing 2.50 mM ammonium acetate. Mass spectrometric detection was performed using electrospray positive ionization with multiple reaction monitoring mode. This method was validated from 0.250 to 100 ng mL⁻¹ for temsirolimus and 0.100 to 40.0 ng mL⁻¹ for sirolimus. The lower limits of quantitation were 0.25 ng mL⁻¹ for temsirolimus and 0.1 ng mL⁻¹ for sirolimus. The intra-day and inter-day precisions (CV %) of spiked quality control (QC) samples were less than 10.4 and 9.6 %, respectively. The accuracies as determined by the relative error for QC samples were less than 12.1 % for intra-day and 7.3 % for inter-day. No significant matrix effect was observed. This method has been successfully applied to analyze clinical pharmacokinetic study samples. The assay reproducibility was also demonstrated by using incurred samples.

     

高效液相色谱-荧光检测法测定血浆中总同型半胱氨酸

 建立了测定血浆中总同型半胱氨酸的柱前衍生、高效液相色谱-荧光检测的分析方法。以Br omobimane作荧光剂,对巯基进行衍生。同型半胱氨酸的最低检测浓度为0.5 μmol/L,线性 浓度范围是2.5～80.0 μmol/L,回收率为94.0%～112.0%,批内、批间相对标准偏差都小于5. 6%。 关键词：     

离子色谱法测定卷烟主流烟气中的硫化氢

建立了测定卷烟主流烟气中硫化氢含量的离子色谱法.采用玻璃纤维滤片捕集卷烟烟气粒相物,并用0.5%(体积分数)乙二胺-50 mmol/L氢氧化钠-250 mmol/L乙酸钠溶液萃取粒相物,吸收液吸收气相物中的硫化氢,合并粒相萃取液与气相吸收液,经离子色谱柱分离,以1.5 mol/L氢氧化钠-1 mol/L乙酸钠-2%(体积分数)乙二胺(40∶50∶10,体积比)为流动相,安培检测器检测并施加-100 mv的检测电位.运用方法对12种市售卷烟样品进行了测定,结果表明:方法的线性范围为0.1~5.0μg/mL,检出限为1.03μg/mL,定量限为3.41μg/mL,回收率为102.3%~107.2%,相对标准偏差小于5%.方法处理简单、准确度高,可以用于卷烟烟气中硫化氢含量的测定.     

金属硫蛋白的色谱/电喷雾电离质谱联用表征方法

通过反相液相色谱(RPLC)与电喷雾电离质谱(ESI-MS)的联用技术,对镉诱导金属硫蛋白标准物质MT-1和MT-2的结构进行表征分析。采用Vydac C8 反相色谱柱(250 mm×2.1 mm i.d., 5 μm, 30 nm),流动相A为pH 6.0的5 mmol/L乙酸铵水溶液,流动相B为pH 6.0的5 mmol/L乙酸铵的甲醇-水(体积比为1∶1)溶液,流动相流速为0.20 mL/min,在40 min内流动相B的体积分数从10%增加到37.5%进行梯度洗脱。分别用紫外(UV)和ESI-M     

g-C3 N4 富集结合毛细管电泳与电感耦合等离子体质谱联用分析西瓜中硒形态

硒是人体所必需的微量元素之一,对人身体健康非常重要。该工作称取2.0 g三聚氰胺于反应釜中,在600℃下密闭加热2 h,冷却至室温,取0.5 g上述产物置于烧杯中在室温下超声10 h,静置30 min,取上层乳白色溶液于60℃下烘干,即得类石墨烯氮化碳（g-C₃ N₄ ）。所制备的g-C₃ N₄ 经傅里叶变换红外光谱（FT-IR）、X射线粉末衍射（XRD）、场发射环境扫描电子显微镜（SEM）进行表征,证明g-C₃ N₄ 已经成功合成。建立了毛细管电泳-电感耦合等离子体质谱（CE-ICP-MS）联用技术测定西瓜中硒形态的新方法。用胃蛋白酶作提取剂及超声波辅助提取西瓜中的硒形态,经g-C₃ N₄ 富集、长100 cm内径100 μm毛细管分离,电泳电压为22 kV,缓冲液为8 mmol/L NaH₂ PO₄ -12 mmol/L H₃ BO₃ -0.2 mmol/L十六烷基三甲基溴化铵（CTAB）（pH 9.2）,于11 min内完全分离6种硒形态。所建立的方法检测速度快、灵敏度高,采用CH₄ 作动态反应气消除干扰。硒脲（SeUr）、硒代胱氨酸（SeCys₂ ）、硒代蛋氨酸（SeMet）、亚硒酸钠（Se（Ⅳ））、硒酸钠（Se（Ⅵ））、硒代乙硫氨酸（SeEt）的线性范围（按Se计）分别为0.017~20 μg/L、0.091~50 μg/L、0.032~40 μg/L、0.023~60 μg/L、0.015~75 μg/L、0.015~30 μg/L。各硒形态的线性相关系数均大于0.9995,SeUr、SeCys₂ 、SeMet、Se（Ⅳ）、Se（Ⅵ）、SeEt的检出限分别为6.2、30、11、8.2、48、5.5 ng/L,回收率为96.0%~106%,RSD < 3%。将本方法应用于西瓜中硒形态分析,结果令人满意。     

Extraction of gadolinium from El-Garra El-Hamra rare-earth cake,South Western Desert,Egypt

The study area of El-Garra El-Hamra is one of the igneous masses located in the southern part of the Western Desert of Egypt. This work has been carried out to investigate the process of gadolinium separation from REEs cake obtained from El-Garra El-Hamra ore concentrate. It is considered as a new approach in the Nuclear Materials Authority of Egypt. Firstly; the optimum leaching conditions achieved are 200 gm/L H₂SO₄, 1/2 solid/liquid ratio, 4 h agitation time,?125 mesh size and at 90 ^°C temperature. Then by solvent extraction method using 1 mol/L D2EHPA middle REEs were extracted. The organic extractant was stripped by using 2 mol/L HCl and Gd pregnant solution was obtained. Then, the relevant optimum factors were 0.3 mol/L D2EHPA diluted by kerosene, 10 min contact time, and 4/1 organic/aqueous ratio giving 87 % Gd extraction. Then, the scrubbing of the loaded extractant was by 1 mol/L HCL followed by Gd stripping using 5 M HCl, contact time of 30 min and 1/3 organic/aqueous ratio. The strip solution was subjected to evaporation and little amount was dried to obtain GdCl₃ powder having a purity of about 81 % associated with YCl₃ 4 %.     

水产品中甲基汞测定的液相色谱-原子荧光光谱联用方法的改进

对本实验室前期建立的食品中甲基汞的液相色谱-原子荧光光谱联用测定方法进行了改进。采用无毒的半胱氨酸代替有毒试剂巯基乙醇作为流动相中的配位剂,流动相组成为5%(v/v)乙腈-1 g/L半胱氨酸-50 mmol/L乙酸铵水溶液,使汞化合物分离时间缩短至8 min。在优化条件下,甲基汞标准曲线的线性范围为1～50 μg/L,检出限(S/N=3)为0.3 μg/L。采用超声波辅助5 mol/L HCl提取样品中的甲基汞,提取液经C18固相萃取小柱净化后进样。鱼、虾、贝等不同种类水产动物样品以及水产类膳食样品的甲基汞加标回收率为89%～112%。对标准参考物质NIST1566b、BCR464和GBW10029以及英国食品分析水平评估计划(Food Analysis Performance Assessment Scheme, FAPAS)的罐装鱼肉样品(样品编号07115)的测定结果与参考物定值相符,验证了该方法的可靠性与准确性。本方法可满足食品中甲基汞检测的需要。     

Ultrasound‐Promoted Magnesium‐Ammonium Bromide–Mediated Pinacol Coupling of Aromatic Aldehydes and Ketones

Pinacol coupling of aromatic aldehydes and ketones by Mg powder in 0.1‐mol/L ammonium bromide aqueous solution can lead to the corresponding pinacols in 22–90% yields within 1–3 h at rt under ultrasound irradiation.     

高效液相色谱-串联质谱法测定化妆品中的欧前胡素和异欧前胡素

建立了化妆品中欧前胡素和异欧前胡素的高效液相色谱-串联质谱(HPLC-MS/MS)测定与确证方法。样品经甲醇提取,以C18柱为分离柱,10 mmol/L乙酸铵/甲醇溶液-5 mmol/L乙酸铵水溶液(80:20, v/v)为流动相分离,采用电喷雾串联四极杆质谱进行检测。欧前胡素和异欧前胡素在0.25～20 μg/L内线性良好(相关系数大于0.999);方法定量限(LOQ)为0.50 mg/kg。在0.50～10.0 mg/kg内,欧前胡素和异欧前胡素的回收率范围分别为82.2%～105%和80.0%～103%,相对标准偏差分别为2.7%～4.9%和1.8%～4.6%。该方法能够满足化妆品中欧前胡素和异欧前胡素检测的需要。     

Determination of 19 Preservatives in Various Matrices by High-Performance Liquid Chromatography

A simple and sensitive high-performance liquid chromatography (HPLC) method was developed for the determination of 19 preservatives in cosmetic matrices. The composition of the mobile phase was optimized as a gradient to achieve a lower detection limit when compared to previously validated methods, and sample preparation conditions were investigated to optimize separation of the 19 preservatives. A C18 column was used with methanol, 0.05 mol/L ammonium acetate buffer, and water as the mobile phase under gradient elution conditions. Preservatives in cosmetics were extracted with 70% methanol using an ultrasonicator, after which they were analyzed with an HPLC-photodiode array detector. All preservatives were separated within 55 min. The recoveries ranged from 94.9% to 102.8%, with relative standard deviations of less than 3.2% and no correlation coefficients lower than 0.9986. Additionally, the developed method has a low detection limit, which makes it possible to analyze trace levels of compounds in various cosmetic and ingredient matrices.     

反相高效液相色谱-蒸发光散射检测法测定紫苏子油中的α-亚麻酸

建立了反相高效液相色谱-蒸发光散射检测器(RP-HPLC-ELSD)测定紫苏子油中α-亚麻酸含量的方法。紫苏子油样用0.5 mol/L的KOH-CH3OH溶液于60 ℃水浴中皂化20 min、6 mol/L的盐酸酸化后用无水乙醚萃取,再用氮气流吹干乙醚，用甲醇溶解并定容,然后直接进行RP-HPLC-ELSD分析。结果表明,当α-亚麻酸质量为6.2～45.4 μg时,其峰面积A的对数(lg A)与α-亚麻酸质量m(μg)的对数(lg m)呈线性关系,线性方程为lg A=1.3675·lg m－1.628,相关系数为0.9973(n＝5)。以信噪比S/N=3计算,方法的检出限为0.11 μg。被分析的紫苏子油中α-亚麻酸的含量为6.79%(质量分数),相对标准偏差(RSD)为5.1%(n=5)；平均回收率为102%,RSD为6.3%(n=5)。该方法简单、快速、准确。     

Simultaneous Determination of Palladium,Platinum and Rhodium by On‐Line Column Enrichment and a Rapid Column High Performance Liquid Chromatography with 2‐Carboxyl‐1‐Naphthalthiorhodamine as Precolumn Derivatization Reagent

Abstract

In this paper, 2‐carboxyl‐1‐naphthalthiorhodamine (CNTR) was synthesized, and a new method for the simultaneous determination of palladium, platinum, and rhodium ions as metal‐CNTR chelates was developed using rapid column high performance liquid chromatography combined with on‐line enrichment. The palladium, platinum, and rhodium ions were precolumn derivatized with CNTR to form colored chelates. The Pb‐CNTR, Pt‐CNTR, and Rh‐CNTR chelates could be absorbed onto the front of the enrichment column when they were injected into the injector and sent to the enrichment column (ZORBAX Stable Bound, 4.6×10 mm, 1.8 µm) with a buffer solution of 0.05 mol/L sodium acetate–acetic acid buffer solution (pH 3.5) as mobile phase. After enrichment, and by switching the six ports switching valve, the retained chelates were back‐flushed by mobile phase and traveling towards the analytical column. The separation of these chelates on the analytical column (ZORBAX Stable Bound, 4.6×50 mm, 1.8 µm) was satisfactory with 54% methanol (v/v) in 0.05 mol/L sodium acetate buffer (pH 3.5) containing 1 g/L Triton X‐100 as mobile phase. Palladium, platinum, and rhodium were separated completely within 2 min. The detection limits (S/N=3) of palladium, platinum, and rhodium are 1.4 ng/L, 1.2 ng/L, and 1.8 ng/L, respectively. This method was applied to the determination of palladium, platinum, and rhodium in water, urine, and soil samples with good results.     

反相离子对色谱/蒸发光散射检测器分离唑来膦酸及其有关物质

采用反相离子对高效液相色谱／蒸发光散射检测法研究了唑来膦酸及其有关物质的色谱分析与分离方法。优化了色谱条件，固定相为Hypersil C8柱，以含10 mmol／L正戊胺的5mmol／L乙酸铵缓冲液（用乙酸调节pH至7．0）-甲醇（体积比为97：3）为流动相，流速为1．0mL/min，蒸发光散射检测器检测。在该色谱条件下，唑来膦酸与其有关化合物（包括合成过程中残余的原料咪唑乙酸及分解产物亚磷酸、磷酸盐）的分离良好，唑来膦酸色谱峰与最近杂质峰的分离度大于1．5。本法简便快速，为唑来膦酸的常规分析提供了有效可靠的方法。