Analysis of Monosaccharide Composition of Pu-erh Tea Polysaccaride by Pre-column Derivatization HPLC

[Objective] This study aimed to establish a pre-column derivatization HPLC method for the identification and analysis of monosaccharide composition of Pu-erh tea polysaccharide. [Method] Pu-erh tea polysaccharide was extracted using the wa- ter extraction method, further isolated and purified by DEAE cellulose-52 columns. The obtained tea polysaccharide and four components TPS1, TPS2, TPS3 and TPS, were first derived by 1-phenyl-3-methyl-5-pyrazolone （PMP）, and then the PMP derivatives of monosaccharide were analyzed by high performance liquid chromatog- raphy （HPLC）. [Result] Pu-erh tea polysaccharide contained eight kinds of monosac- chaddes （mannose, rhamnose, glucuronic acid, galacturonic acid, grucose, galactose, arabinose, fucose）, without xylose; so it was the same with TPS1; each of TPS2, TPS3 and TPS4 contained seven monosaccharides, while no fucose. [Conclusion] This method is simplified and rapid, which can be used to determine the monosac- charide composition of Pu-erh tea polysaccharide and monosaccharide content.

Determination of Sparfloxacin in Human Urine by Reversed-Phase High Performance Liquid Chromatography With Nitrous Acid and Hydroiodic Pre-Column Derivatization

Sparfloxacin can be oxidized by nitrous acid, then react with hydroiodic acid to form a fluorescent derivative. Based on this, a reversed-phase high performance liquid chromatographic pre-column derivatization new method is described for the determination of sparfloxacin in human urine. The linear range is 0.05 mg/L to 4.0 mg/L, the recoveries are 91.5%similar to 95.7% and the RSD is 1.2%similar to4.2%. The results showed that this method is suitable for the determination of sparfloxacin in human urine.

Determination of 18 Kinds of Amino Acids in Fresh Tea Leaves by HPLC Coupled with Pre-column Derivatization

A rapid and accurate quantitative method of high performance liquid chromatography( HPLC) with fluorescence detector has been developed for the analysis of 18 kinds of amino acids in fresh tea leaves. The samples were minced and mixed,and extracted with ultra pure water at 90℃ for 20 min. The 6-aminoquinolyl N-hydroxy-succinimidyl carbamate( AQC) was used as pre-column derivatization reagent. Gradient HPLC separation was performed on a C_(18) column( Symmetry C_(18),3. 9 mm × 15 cm,4 μm). Good linearity between concentrations and peak areas was achieved in the concentration range of 5. 0-250 μmol/L for 18 kinds of amino acids. The method was validated by the analysis of five replicates. The 18 kinds of amino acid standards were spiked in fresh tea leaf samples and the average recovery rate was 86. 25%-109. 05% with relative standard deviations( n = 5) ranging from 6. 03% to 10. 56%. The limit of detection( LOD) for the analytes was0. 05-1. 27 μmol/L. The method was successfully applied to the analysis of the 18 kinds of amino acids in fresh tea leaves from east Dongting and west Dongting mountains in Suzhou. The results indicate that the method is simple,rapid,precise and reliable.

Enantioresolution of a Series of Chiral Benzyl Alcohols by HPLC on a Dinitrobenzoylphenylglycine Stationary Phase after Achiral Pre-Column Derivatization

High performance liquid chromatography method for the separation of a series of chiral benzyl alcohols on N-(3,5-dinitrobenzoyl)-D-phenylglycine stationary phase (Macherey Nagel, Chiral-2) after pre-column achiral derivatization was developed. Cheap and easy available aromatic acid chlorides were used as derivatization agents. Good to excellent separations of the enantiomers were achieved in all cases in relatively short analytical runs. It was shown that the enantiorecognition depends on the substituents both in the starting alcohol and in the acid chloride. The method presents an efficient alternative to the direct analyses on polysaccharide and cyclodextrine-derived stationary phases.

HPLC of Amino Acids and Oligopeptides by Pre-Column Fluorescence Derivatization with 9-Acridine Formyl Chloride

A highly sensitive HPLC method for the detection of amino acids and oligopeptides with 9-acridine formyl chloride by pre-column fluorescence derivatization has been developed. Glycine, glycylglycine, histidine, triglycine and glutathione were separated on a reversed-phase C-18 column with methanol-water-triethylamine eluent, derivatization and chromatographic conditions were optimized. The five derivatives were eluted in 28 min with a good reproducibility. Linear range of the calibration graph was 0.08-260 nmol/ml(-1). The relative standard deviations(n=6) are < 5%. Detection limits (signal-to-noise ratio=3) for the five derivatives are 20-40 fmol.

气相色谱-质谱法测定水体中5种典型有机紫外防晒剂

建立了水体中5种典型有机紫外防晒剂甲氧基肉桂酸乙基己酯（ethylhexyl methoxycinnamate，EHMC）、二苯酮-3（benzophenone-3，BP-3）、4-甲基苄亚基樟脑（4-methylbenzylidene camphor，4-MBC）、奥克立林（ octo-crylene，OC）和胡莫柳酯（homosalate，HMS）的气相色谱-质谱检测方法。对 HMS、BP-3衍生化条件进行了系统的优化。以100μL 双（三甲基硅烷基）三氟乙酰胺（ N，O-bis（ trimethylsilyl）trifluoroacetamide，BSTFA）为衍生化试剂，在100℃下反应100 min。水样固相萃取选用 Oasis HLB 萃取柱（0.5 g），洗脱溶剂为乙酸乙酯-二氯甲烷（1∶1，v / v），水样 pH 3~5。该方法对5种化合物的检出限范围为0.5~1.2 ng / L，定量限范围为1.4~4.0 ng / L。最佳实验条件下，加标水样回收率为87.85％~102.34％，相对标准偏差（n ＝3）均小于5％。该方法成功地应用于昆明市第一污水厂进出口水样中目标物质的分析。

柱前紫外衍生-高效液相色谱法测定全氟辛酸

目的建立污水和尿液中全氟辛酸（PFOA）的柱前紫外衍生一高效液相色谱测定方法。方法样品中的PFOA与四丁基氢氧化铵形成的离子缔合物被甲基叔丁基醚萃取后，与ω-溴苯乙酮在乙腈中衍生成具有紫外吸收的物质，高效液相色谱-紫外可见检测器检测。结果方法检出限可达7．0μg／L；相对标准偏差（RSD）〈10％；样品的回收率在85．3％～116％之间。结论本法适用于测定水样及尿液中的全氟辛酸。

高效液相色谱-紫外检测法测定纺织品中PFOA

PFOA自身无紫外活性,在采用紫外光测定其含量时,必须先对其进行衍生反应。试验以二甲苯为溶剂,中性氧化铝为催化剂,在140℃、氮气保护条件下,使苄胺与全氟辛酸(体积分数比为1∶2.0)反应10 h,合成PFOA酰胺化衍生物N-苄基十五氟辛酰胺[CF3(CF2)6CONHCH2Ph],产物在248 nm处摩尔吸收系数达到103以上,具有较高的紫外分析灵敏度,可以间接测定纺织品中痕量全氟辛酸。

高效液相色谱紫外检测法测定血浆中总半胱氨酸

建立了一种柱前衍生高效液相色谱-紫外检测法测定血浆总半胱氨酸的方法。以tris-(2-carboxylethyl)-phosphine(TCEP)为还原剂,7-fluorbenzo-2-oxa-1,3-diazole-4-sulfonate(SBD-F)为衍生剂,N-乙酰半胱氨酸为内标,C8色谱柱分离,流动相为甲醇-磷酸盐缓冲液(pH=3.0),梯度洗脱,385nm处检测。线性范围为8.3～1042.6μmol/L,最低检测限为0.42μmol/L,日内精密度为1.67%～1.86%,日间精密度为2.08%～3.06%,平均回收率为98.1%～103.2%。

柱后紫外光解荧光衍生液相色谱法测定蔬菜中残留的15种苯脲除草剂

建立了蔬菜中15种苯脲除草剂残留的固相萃取-在线柱后紫外光分解和衍生化的高效液相色谱荧光检测分析方法。样品用乙腈提取,弗罗里硅土固相萃取柱净化,目标化合物由反相C18柱分离,经柱后紫外光分解和衍生化后进行荧光检测。对样品的前处理条件、液相色谱分离、柱后紫外光分解和衍生条件等进行了详细的研究。15种苯脲除草剂的高效液相色谱分离在乙腈-水梯度洗脱下完成,目标物的保留时间为9-31m in,线性范围内线性关系良好,相关系数为0.998 6-1.000 0;在洋葱、菠菜、黄瓜等样品中3个加标水平的平均回收率（n=3）为75.3%-121.6%,相对标准偏差为0.4%-11.6%;15种苯脲除草剂在蔬菜中的检出限为0.005-0.05m g/kg。该方法操作简便、灵敏度高、选择性好,符合多种农药残留分析的要求。

柱后衍生-离子色谱-紫外检测法测定食品中亚硝酸盐含量

目的建立柱后衍生-离子色谱-紫外检测法测定食品中亚硝酸盐含量的分析方法。方法样品用水进行超声提取,采用亚铁氰化钾-乙酸锌溶液沉淀后离心过滤,样品溶液中的亚硝酸盐经离子色谱分离后在酸性条件下与对氨基苯磺酸及N-(1-萘基)-乙二胺二盐酸盐偶合生成紫红色染料,紫外检测器在538 nm波长下检测,外标法定量。结果以KOH溶液为流动相,亚硝酸盐在0.001~0.100 mg/L质量浓度范围内线性良好,检出限低至0.05 mg/kg,食品样品中亚硝酸盐的加标回收率在90.4%~109.0%之间,6次重复测量的相对标准偏差均小于10%。结论本方法具有灵敏度高、特异性强、前处理简便等优点,适合于各种类型样品中亚硝酸盐的检测。

分散液液微萃取-在线衍生化-气相色谱-质谱联用法检测环境水样品中紫外吸收剂

建立了分散液液微萃取（ dispersive liquid-liquid microextraction，DLLME ）-在线衍生化-气相色谱-质谱（ GC-MS）方法，将其用于环境水中6种二苯甲酮类紫外吸收剂（ BPs）（二苯甲酮、2，4-二羟基二苯甲酮、2-羟基-4-甲氧基二苯甲酮、4-羟基二苯甲酮、2-羟基-4-辛氧基二苯甲酮、2，2′-二羟基-4，4′-二甲氧基二苯甲酮）的检测。系统优化了在线衍生化的条件（如进样口温度、不分流时间、衍生化试剂用量）以及 DLLME 萃取条件（如萃取剂种类、分散剂种类、萃取剂与分散剂比例、样品体积、样品溶液离子强度及 pH 值）等。在最优的条件下，所考察的6种BPs检出限为0.011~0.15μg/L，重现性（ RSD）为0.7％-16.6％。该方法结果准确可靠，操作简单，富集效果好，成本较低，环境友好，在实际样品检测中具有一定的应用前景。

全氟辛酸的3,4-二氯苯胺衍生化及高效液相色谱分析

介绍了一种可用于环境污染物全氟辛酸（PFOA）检测的高效液相色谱/紫外检测（HPLC/UV）分析方法。首先选用3,4-二氯苯胺为衍生化试剂,利用碳二亚胺法合成PFOA的酰胺化衍生产物（其在255 nm处紫外吸收最大）。然后确定四氢呋喃或水相介质中mg/L水平PFOA的衍生化条件及薄层硅胶色谱净化步骤。建立柱前衍生-HPLC/UV方法,以合成的全氟辛酸-3,4-二氯苯酰胺为对照品,外标法定量,PFOA上机测定的定量限为0.5mg/L。通过加标回收试验评价方法的准确性,其中有机相及水相衍生法的回收率分别为91.8%-108.7%及40.1%-53.7%。与已报道的柱前衍生-HPLC/UV方法比较,本方法具有反应条件温和、衍生产物稳定、原料廉价易得、操作简单、成本低等优点。将本方法应用于光催化降解研究中PFOA的降解动力学实验,结果与液相色谱-质谱联用方法（LC/MS）的结果一致,说明本方法具有较好的应用前景。

高效液相色谱法测定1-三甲基硅基-1-炔-3-癸醇对映体纯度

以苯甲酰氯试剂衍生1-三甲基硅基-1-炔-3-癸醇,得到具有强紫外吸收的1-三甲基硅基-1-癸炔-3-苯甲酸酯.考察流动相中不同醇调节剂、乙醇含量和柱温对外消旋1-三甲基硅基-1-癸炔-3-苯甲酸酯对映体在Chiralcel OD-H手性柱上色谱分离的影响,建立测定1-三甲基硅基-1-炔-3-癸醇对映体纯度的色谱分析方法.结果表明:以正己烷-乙醇(99.950.05,体积比)为流动相,检测波长为228nm,外消旋苯甲酰氯衍生对映体在Chiralcel OD-H柱上得到很好的分离,保留时间分别为6.94min和8.11min,分离因子和分辨率分别为1.41和3.75.本法灵敏度高,方法简便,适合于手性1-三甲基硅基-1-炔-3-癸醇样品的对映体纯度分析.

离子色谱柱后衍生紫外法测定面制品中的水溶性硅酸盐

目的建立离子色谱柱后衍生紫外检测法测定面制品中水溶性硅酸盐含量的分析方法。方法面制品经烘干、粉碎后,称取适量样品,以水为溶剂超声提取30 min,随后在10000 r/min转速下离心10 min,上清液经0.22μm微孔滤膜过滤后待上机分析。以25 mmol/L NaOH-0.5 mmol/L Na2CO_(3)为淋洗液,流速0.7 mL/min,柱温45℃,进样量250μL。柱后衍生试剂为200 mmol/L HNO_(3)+20 mmol/L钼酸钠溶液,衍生试剂流速0.3 mL/min,衍生反应温度45℃,紫外检测器波长设定为360 nm,外标法定量。结果硅酸根离子在0.01~0.80 mg/L浓度范围内线性关系良好,相关系数为0.9999,方法检出限为0.005 mg/L(以SiO_(3)^(2-)计)。面制品样品的加标回收率介于98.4%~106.0%之间,相对标准偏差为4.5%~6.3%(n=3)。采用本方法测定了46种市售面制品(包括碱水面)中硅酸根离子的含量,面制品中硅酸根离子含量在4.64~51.15 mg/kg之间。结论本方法选择性和灵敏度高、准确性好、分析速度快,尤其适合大批量面制品样品中可溶性硅酸盐含量的测定。

在线衍生-膜进样-VUV电离-飞行时间质谱法测定废水中酚类化合物

酚类化合物是染料、炼焦、造纸等工业废水中的主要污染物,污染范围广、危害大,因此有必要发展在线灵敏的测量方法对其进行监测和控制。我们利用自主研制的膜进样-真空紫外(VUV)电离-飞行时间质谱仪(time of flight mass spectrometer,TOFMS),发展了一种快速测量水中苯酚、3-甲酚、2-氯酚和2,4-二氯酚的方法。实验发现:经乙酸酐衍生化反应后,酚类化合物的检测灵敏度可以大大提高;用聚二甲基硅烷(PDMS)膜直接进样可以缩短样品的分析检测时间,使单个样品的分析时间小于15 min。同时,由于单光子电离技术产生的碎片峰很少,谱图解析方便,可以不用分离直接测量混合物样品。优化实验参数(反应时间、pH值、乙酸酐加入量等)后,苯酚、3-甲酚、2-氯酚和2,4-二氯酚的检出限分别达到3、6、8、14μg.L-1,线性范围达到2个数量级。

Reversed-phase high-performance liquid chromatographic analysis of seven pairs of chiral drug enantiomers in transport medium after chiral derivatization

A reversed-phase high-performance liquid chromatographic （RP-HPLC） method was established for the determination of the enantiomers of 7 aryloxy aminopropanol drugs （atenolol, sotalol, celiprolol, carvedilol, metoprolol, propranolol and propafenone） in transport medium. The method involved liquid-liquid extraction of chiral drugs from transport medium, and employed 2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl isothiocyanate （GITC, 1.0 mg/mL in acetonitrile） as a pre-column chiral derivatization reagent. After derivatization, the products were separated on an Agilent Zorbax C8 column （150 min×4.6 mm, 5 μm） at 25 ℃. The mobile phase consisted of a mixture of acetonitrile and 0.01 M phosphate buffer （pH 3.5）. The present methods were specific for the determination of enantiomers of each chiral drug. The absolute recoveries of the enantiomers and internal standards were 〉78%. The relative recoveries of the enantiomers were approximately 100%. The intra- and inter-day variations were 〈 15%. The method was reproducible and sufficiently sensitive to determine the enantiomers of seven aryloxy aminopropanol drugs in transport medium. The method could be used to study the transport of atenolol, sotalol, celiprolol, carvedilol, metoprolol, propranolol and propafenone.

Evaluation of Baishao(Radix Paeoniae Alba)and Chishao(Radix Paeoniae Rubra)from different origins based on characteristic spectra of amino acids

Objective To evaluate the difference between Baishao(Paeoniae Radix Alba,PRA)and Chishao(Paeoniae Radix Rubra,PRR)from different regions based on the characteristic spectra of amino acids(AAs).Methods Fingerprints of the 21 standard AAs were established using O-phthalaldehyde-9-fluorenylmethyl chloroformate(OPA-FMOC)pre-column derivation method.The AA components in PRA and PRR were characterized qualitatively and quantitatively,and different AAs were screened using pattern recognition technology.Results Twelve AAs were identified in both PRA and PRR.Meanwhile,aspartic acid,glutamic acid,arginine,alanine,and gamma-aminobutyric acid were screened as characteristic components,and their concentrations could effectively distinguish PRA from PRR.Conclusion The established characterization method,which is based on the characteristic spectra of AAs,is accurate,efficient,and sensitive and can effectively distinguish between PRA and PRR from different producing areas,thus providing a reference for the overall characterization and evaluation of Chinese medicinal materials.

离子色谱-柱后衍生-紫外可见检测法测定涂料中六价铬含量

采用碱提取,离子色谱-柱后衍生-紫外可见检测法测定涂料色漆中六价铬含量。确定了试验相关参数,进行了方法的线性、检出限、精密度和准确度探讨并与分光光度法进行了比较。本方法可在3分钟内完成分析,六价铬峰型良好,曲线线性范围:低浓度,0.005~0.050 mg/L,相关系数≥0.9992,方法检出限0.08 mg/kg。高浓度,0.10~1.00 mg/L,相关系数≥0.9999,方法检出限1.3 mg/kg,精密度和准确度较高,3个色漆实际样品的加标回收率为86.5%~116.0%,RSD为3.0%~3.7%(n=7)。方法时间短、线性范围宽,选择性强、灵敏度高、检出限低、不需要调节pH至酸性、样品保存时间长,相较常规紫外可见分光光度法能够更好地满足涂料色漆中六价铬测定的实际需要,满足GB/T 35602-2017测定的要求。

高效液相色谱-柱后紫外衍生测定植物油中黄曲霉毒素的方法研究

对自制柱后紫外衍生器与厂家的紫外衍生器进行了性能对比试验,结果显示样品信号值基本一致。使用自制紫外衍生器与未使用相比,吸光效率增加约15倍;稳定性试验测定的相对标准偏差为2.13%,满足GB/T 27404—2008要求。同时对黄曲霉毒素样品进行了回收试验,回收率达98.0%。结果证明自制紫外衍生器能用于黄曲霉毒素测定的柱后衍生,满足实验室测定要求。