高效毛细管电泳 间接紫外吸收检测法测定食品中的氨基酸

研究了鸟氨酸、脯氨酸和谷氨酰胺的高效毛细管电泳 间接紫外吸收检测的特征。以5　mmol/L 对氨基苯磺酸钠 10 mmol/L KH2PO4(pH 11.5)为运行缓冲液,在分离电压12 kV下,于11 min实现了上述3种氨基酸的基线分离,迁移时间和峰高的相对标准偏差分别小于0.72%和2.0%,检测限分别为6.78,8.71,7.86 mg/L。应用该法测定食品中的氨基酸及各氨基酸在样品中的加标回收率,3种氨基酸的加标回收率为96.8%~104%。     

毛细管区带电泳-间接紫外检测法快速测定食品中乳糖、蔗糖、葡萄糖和果糖

建立了毛细管区带电泳-间接紫外检测快速测定食品中乳糖、蔗糖、葡萄糖和果糖的方法。以水或5 mmol/L醋酸为样品提取液,未涂层熔融石英毛细管(30.2 cm(有效长度20 cm)×50 μm)为分离柱,4 mmol/L山梨酸钾+10 mmol/L磷酸钠+30 mmol/L NaOH(pH 12.56)+0.5 mmol/L十六烷基三甲基溴化铵(CTAB)为分离缓冲液,在-8 kV下分离,于254 nm波长下检测,10 min内实现了食品中上述4种糖的同时分离与测定。乳糖、蔗糖、葡萄糖和果糖的检出限(S/N=3)分别为50、75、25和25 mg/L,定量限(S/N=10)分别为150、225、75和75 mg/L,回收率在87.0%~107.0%之间,相对标准偏差在1.2%~4.7%之间。整个实验过程未使用有机溶剂。用该法测定了9种食品样品及1个质控样品,结果表明该法简单、快速、准确,适用于食品中乳糖、蔗糖、葡萄糖和果糖的日常测定。     

毛细管电泳法分析西维因等农药

 采用毛细管电泳法对西维因和 4种三嗪类农药进行了分离研究 ,考察了溶液的 pH值、胶束浓度和有机改性剂对分离的影响。以 2 0mmol/L硼砂 5 0mmol/L十二烷基硫酸钠 10 % (体积分数 )甲醇溶液 (pH 9 2 )为电泳缓冲液 ,采用压力进样方式 ,在 2 5kV恒压下进行分离 ,并在波长 2 2 5nm处检测 ,各组分可达到基线分离。在质量浓度为 30mg/L～ 2 0 0mg/L时 ,西维因标样的线性关系良好。该方法应用于西维因原药实际样品的测定 ,结果令人满意 ,西维因的加标回收率为 93 4 %～10 1 3% ,其峰面积的RSD为 2 5 9%。     

毛细管电泳-场强放大堆积技术对制剂中磺胺嘧啶和磺胺甲噁唑的测定研究

利用高效毛细管电泳-场强放大柱内堆积技术分离测定磺胺嘧啶(SD)和磺胺甲噁唑(SMZ)。采用未涂层熔融石英毛细管柱(60.2 cm×75μm,有效长度50 cm),以50 mmol/L NaH2PO4(pH6.0)为运行缓冲液,分离电压27.5 kV,柱温25℃,检测波长214 nm进行测定。进样前压力进水3.42 kPa×12 s;电动进样-10kV×9 s。SD和SMZ的线性范围分别是0.05~10.00 mg/L(r=0.999 9),0.025~5.00 mg/L(r=0.999 4),检出限分别为1.74、1.39μg/L;将此方法应用于实际样品测定,SD回收率为98%~103%,SMZ回收率为97%~103%。     

毛细管电泳柱后衍生激光诱导荧光测定动物组织中卡那霉素类抗生素

采用毛细管电泳柱后衍生激光诱导荧光测定3种卡那霉素类抗生素。研究了在反向电渗流条件下HAc-NaAc缓冲液酸度和浓度对卡那霉素类抗生素分离的影响,研究了Na2B4O7缓冲体系和柱后衍生试剂萘二醛/2-巯基乙醇浓度对检测信号的影响。采用50 mmol/L HAc-NaAc(pH5.0) 0.5 mmol/L CTMAB溶液为分离缓冲液,样品在-15 kV下分离,与柱后衍生试剂1.0 mmol/L NDA 8.0 mmol/L 2-ME 35 mmol/LNa2B4O7(pH10.0)的30%(V/V)甲醇溶液反应,激发诱导荧光检测卡那霉素类抗生素检出限为3.6×10-5~5.2×10-5g/L;本方法用于动物组织中卡那霉素类抗生素残留检测,相对标准偏差小于7.2%;回收率为90.2%~95.3%(n=4)。     

胶束电动毛细管电泳法测定β-内酰胺类抗生素

采用胶束电动毛细管电泳(MEKC)法测定多种β-内酰胺类抗生素及舒巴坦的含量。电泳运行缓冲液为20 mmol/L硼砂缓冲液(pH9.5),十二烷基硫酸钠(SDS)38 mmol/L。8种药物在15m in内达到基线分离。选择苯巴比妥作为内标,各组分浓度在50~600 mg/L范围内呈良好线性关系,相关系数为0.9932~0.9993;检出限4.8~26 mg/L;进样精密度RSD 3.0%~5.6%;对头孢哌酮-舒巴坦制剂进行含量测定,回收率为100%~106%,含量测定结果与HPLC方法所得结果没有显著性差异。     

高效毛细管电泳法同时分离测定化妆品中7种防腐剂

建立了毛细管电泳(CE)法同时分离测定化妆品中7种防腐剂(对羟基苯甲酸甲酯、对羟基苯甲酸乙酯、对羟基苯甲酸丙酯、对羟基苯甲酸丁酯、氯苯甘醚、辛酰羟戊酸、脱氢乙酸钠)的方法。考察了添加剂种类及浓度,磷酸盐缓冲液pH值及分离电压对分离的影响。结果表明:在pH 8.0的20 mmol/L磷酸盐缓冲液中添加10 mmol/L磺丁基-β-环糊精,以及20 kV分离电压下,7种防腐剂可在5 min内实现基线分离。在5～200 mg/L质量浓度范围内,7种防腐剂呈良好线性,且相关系数(r)为0.990 7～0.998 9,检出限为1.23～4.30 mg/L,迁移时间的相对标准偏差(RSD)不大于1.3%,样品回收率为95.4%～103%。该方法准确、简单、高效、实用,可用于实际样品中防腐剂的测定。     

微流控芯片非接触电导法测定感冒药中盐酸伪麻黄碱和氢溴酸右美沙芬

研究了用微流控芯片非接触式电导法分离检测感冒药日夜百服咛片中的两种主要成分盐酸伪麻黄碱和氢溴酸右美沙芬的方法。优化条件为:缓冲液20 mmol/L Tris 20 mmol/L H3BO3(pH=8.0);进样电压300 V;进样时间10.0 s;分离电压3.0 kV。非接触电导检测器激发电压60 V(Vp-p),频率60 kHz。两种成分的线性范围分别为20~1000 mg/L和10~1000 mg/L;检出限分别为10和5.0 mg/L;样品回收率分别为99.3%和97.6%。     

胶束毛细管电泳法同时分离四环素与青霉素类药物的研究

采用胶束毛细管电泳(MEKC),建立了四环素(TCs)和青霉素(PENs)两类7种药物同时分离的方法。考察了MEKC中缓冲液类型、离子浓度和pH值,以及表面活性剂(SDS)浓度、分离电压、温度等参数的影响。利用L16(45)正交试验,确立了最佳的电泳条件:缓冲液为40 mmol/L磷酸二氢钾-20 mmol/L硼砂,添加65 mmol/L SDS,pH 7.9,分离电压28 kV,分离温度28℃,紫外检测波长分别为350 nm和200nm。结果表明:7种药物在25 min内得到完全分离。在1.56~50 mg/L范围内呈良好的线性关系,相关系数(r2)为0.997 9~0.999 9,峰面积的相对标准偏差(n=6)为4.1%~7.3%;迁移时间的相对标准偏差(n=6)为0.33%~0.67%。在2.0,5.0,10.0 mg/kg的加标水平下,7种药物的回收率为83.6%~93.3%,相对标准偏差(n=6)为4.7%~7.6%。该法快速、简便、准确,具有较高的灵敏度,已应用于合肥市及周边地区水塘和湖水中7种药物的快速分离检测。     

基于场放大进样富集的微流控芯片-激光诱导荧光法检测奶制品中的β-酪啡肽

基于微流控芯片-激光诱导荧光分析技术,探讨了奶酪中两种β-酪啡肽(β-CM-5和β-CM-7)的场放大进样富集和检测。采用10 mmol/L硼酸-硼砂溶液(pH8.7)作为衍生缓冲液,5 mmol/L硼砂溶液(pH8.9)作为样品缓冲液,进样10s,60 mmol/L硼砂溶液(pH8.9)作为运行缓冲液,分离电压1500V,在120s内成功分离检测了两种β-酪啡肽。实验结果表明,β-CM-5和β-CM-7的富集倍数是16倍和21倍,检出限分别是8.2 nmol/L和3.6 nmol/L,线性范围分别是0.05~2μmol/L和0.02~1μmol/L,加标回收率在86.9%~107.5%,该方法可应用于奶制品中β-CM-5和β-CM-7的含量测定。     

Electrophoretic separation with 2-mm inner diameter fused-silica microcolumn packed with quartz microncrystals and its application

The feasibility of a microcolumn electrophoresis technique was investigated with a 100 mm length, 2 mm I.D. fused-silica microcolumn packed with uniform quartz microncrystals prepared by hydrothermal synthesis. To evaluate the separation technique, tryptophan, phenylalanine and tyrosine were primarily separated by the microcolumn electrophoresis and detected at 216 nm without derivatization by an ordinary spectrophotometer. The separation conditions of the amino acids were optimized. With 1.5 mmol/L disodium phosphate buffer solution (pH 11.5) containing 25% (v/v) methanol and 10% (v/v) acetonitrile, the three amino acids were separated and the separation efficiency of tryptophan was 4.5 × 10⁴ plates/m. The limits of detection were 0.035, 0.22 and 0.20 μmol/L, respectively. The sample capacity of the electrophoretic microcolumn achieved 35 μL. The proposed method was used to determine these amino acids in compound amino acid injection samples without derivatization. For the simplicity and portability of the microcolumn electrophoresis, it is studied as one of the high-performance separation techniques for an in situ and real-time electrokinetic flow analysis system. For its high detection sensitivity and large sample capacity, it can be developed for preparative electrophoresis.     

咔唑-9-乙基氯甲酸酯柱前衍生氨基酸胶束电动色谱分离

采用一种新型紫外、荧光衍生试剂咔唑-9-乙基氯甲酸酯对9种氨基酸(丝氨酸、苏氨酸、甘氨酸、谷氨酸、天冬氨酸、缬氨酸、异亮氨酸、亮氨酸、苯丙氨酸)进行柱前衍生,采用胶束电动色谱模式在14 min内完成分离。分离条件：以pH 9.0的 20 mmol/L硼酸盐-30 mmol/L十二烷基硫酸钠(SDS)溶液（含3%(体积分数)乙腈)为缓冲溶液,柱温25 ℃,分离电压18 kV,紫外检测波长214 nm。该方法的线性范围为0.025~0.25 mmol/L,检出限为2.15~2.46 μmol/L。     

采用隔离池的毛细管电泳-间接紫外吸收法测定茶叶中的氨基酸

改进的毛细管电泳-间接紫外吸收法采用了自制隔离池,以对氨基苯甲酸(PAB)为背景电解质,对茶叶中的氨基酸进行了测定。PAB能够提高分离效率,降低检出限。隔离池的使用避免了PAB的电极反应,降低了基线噪声,维持了两缓冲液池间的电流导通。研究了背景电解质的浓度、pH值以及电渗流改性剂的种类和浓度对氨基酸分离的影响。在优化的实验条件下,16种氨基酸在14 min内达到了基线分离,峰面积的相对标准偏差小于5%(n=5),检出限为1.7~4.5 μmol/L,回收率为83.0%~106%。该法快速、便捷和灵敏,已成功应用于茶叶中11种游离氨基酸的检测。     

Profiling and screening analysis of 27 aromatic amino acids by capillary electrophoresis in dual modes

An efficient capillary electrophoretic (CE) profiling and screening system based on dual modes of capillary zone electrophoresis (CZE) and micellar electrokinetic capillary chromatography (MEKC) was developed for the simultaneous determination of 23 nonprotein amino acids (NPAAs) and 4 protein amino acids with aromatic moiety. It involves separation by an uncoated fused-silica capillary under phosphoric acid buffer in CZE mode and by another uncoated fused-silica capillary under neutral sodium dihydrogen phosphate buffer containing sodium dodecyl sulfate in MEKC mode. Migration orders of the amino acids studied on the two separation modes under each optimum condition were very different. The repeatability of migration times measured by the CZE and MEKC was found to be better than 4.8 and 3.4%, respectively, thereby enabling to cross-check the identification of each amino acid. The method linearity and limit of detection of the CZE for each amino acid were found to be adequate for the assay of aromatic amino acids. When the present CE profiling and screening analysis in dual modes was applied to plant seeds, NPAAs such as mimosine from Mimosa pudica Linné, and 2-phenylglycine from Lindera erythrocarpa Makino were positively detected along with tryptophan, phenylalanine and tyrosine.     

场增强样品堆积-毛细管电泳法测定山楂粉中的氨基酸

采用场增强样品堆积-毛细管电泳法建立了在线富集氨基酸的分析方法,用于中药山楂中水解氨基酸的检测,并进行了回收率实验. 采用富集电压为-20 kV,进样压力为3 psi,进样时间为50 s,紫外检测波长为214 nm,运行缓冲溶液为270 mmol/L乙酸-270 mmol/L乙酸钠（pH=4.15）-6%（V/V）乙腈溶液,分离电压为17 kV,组氨酸、精氨酸、色氨酸、酪氨酸、缬氨酸、苯丙氨酸、亮氨酸、苏氨酸、丙氨酸、甘氨酸、谷氨酸和门冬氨酸等12种氨基酸在50 min内达到分离,检出限在0.000 3~0.08 μg/mL之间.     

分析测试新方法(197~203)毛细管电泳-间接紫外法用于太子参中的非衍生化氨基酸检测

建立了一种简单、快速测定赖氨酸(Lys)、脯氨酸(Pro)、亮氨酸(Leu)、丙氨酸(Ala)、组氨酸(His)、苏氨酸(Thr)、蛋氨酸(Met)、丝氨酸(Ser)和甘氨酸(Gly)的毛细管电泳-间接紫外检测方法.通过研究缓冲液的种类和浓度、缓冲液的p H等分离条件对被测组分分离度和灵敏度的影响,从而优化了分析条件.实验结果表明,用0.1mol/L氢氧化钠溶液调节14 mmol/L的对氨基苯磺酸至p H为11.2做为运行缓冲液,当分离电压为20 k V时,9组分在12 min内实现了完全分离.实验结果表明,方法能成功用于不同产地太子参药材中9种氨基酸的含量测定.方法重现性良好,迁移时间和峰高的RSD分别小于2.6%和4.5%(n=7).     

Capillary electrophoresis direct enantioseparation of aromatic amino acids based on mixed chelate-inclusion complexation of aminoethylamino-beta-cyclodextrin

6(A)-(2-Aminoethylamino)-6(A)-deoxy-beta-cyclodextrin (CDen) was synthesized and formed a binary complex with Cu(II) which was shown to be an effective chiral selector for separation of underivatized amino acid enantiomers in capillary electrophoresis (CE). Moreover, the chiral resolution was greatly enhanced by the presence of polyethyl glycol (PEG) and tert-butyl alcohol in the running buffer. The optimum experimental conditions were 20 mmol/L CDen, 20 mmol/L CuSO(4).5H(2)O, 5.0 mg/mL PEG20000 and 1.0% v/v tert-butyl alcohol, pH 5.80. With the proposed method, the four selected aromatic chiral amino acid pairs were separated in less than 15 min.     

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。     

The use of ethylene glycol solution as the running buffer for highly efficient microchip-based electrophoresis in unmodified cyclic olefin copolymer microchips

An ethylene glycol solution was used as the electrophoretic running buffer in unmodified cyclic olefin copolymer (COC) microchips to minimize the interactions between the analytes and the hydrophobic walls of the plastic microchannels, enhance the resolution of the analytes and eliminate the uncontrollable dispersion caused by uneven liquid levels and non-uniform surfaces of the separation channels. Five amino acids that were labeled with fluorescein isothiocyanate (FITC) were used as model analytes to examine the separation efficiency. The effects of ethylene glycol concentration, pH and sodium tetraborate concentration were systematically investigated. The five FITC-labeled amino acids were effectively resolved using a COC microchip with an effective length of 2.5 cm under optimum conditions, which included using a running buffer of 20 mmol/L sodium tetraborate in ethylene glycol:water (80:20, v/v), pH 6.7. A theoretical plate number of 4.8 × 10(5)/m was obtained for aspartic acid. The system exhibited good repeatability, and the relative standard deviations (n=5) of the peak areas and migration times were no more than 3.4% and 0.7%, respectively. Furthermore, the system was successfully applied to elucidate these five amino acids in human saliva.     

毛细管电泳柠檬酸-Zn2+体系对异亮氨酸对映体的手性分离

应用毛细管电泳/电容耦合非接触式电导（CE-C⁴D）分离检测技术,研究了柠檬酸-Zn²⁺体系对异亮氨酸对映体的手性识别行为。结果表明,采用未涂层石英毛细管（45 cm×50 μm,L_eff=40 cm）,以2.8 mmol/L NaOH+0.8 mmol/L柠檬酸+2.0 mmol/L乙酸锌为非手性介质电泳运行液,分离电压+13 kV,D,L-异亮氨酸对映体得到了良好的手性识别,对映体分离度达到2.0。线性检测范围为1.0~20 mg/L,检出限（S/N=3）为0.40 mg/L。对影响分离度的因素（Zn²⁺的浓度、电泳运行液的组成、分离电压以及其他氨基酸的干扰情况等）进行了详细的讨论,并对手性识别机理作了初步探讨。