2-[2-(7H-二苯并[a,g]咔唑)-乙氧基]-乙基氯甲酸酯对脂肪胺类化合物的荧光标记及质谱鉴定

利用新型荧光标记试剂2-[2-(7H-二苯并[a,g]咔唑-乙氧基)-乙基氯甲酸酯作为柱前衍生化试剂, 在Eclipse XDB-C8反相色谱柱上,采用梯度洗脱,实现了12种脂肪胺类化合物完全基线分离.检测最佳激发和发射波长分别为300和400 nm.通过荧光检测及离子阱大气压化学电离源(APCI Source)正离子模式实现了在线的柱后质谱鉴定.对土壤中脂肪胺类化合物的测定快速、准确,具有良好的重现性.荧光定量检测的回归系数大于0.9991; 检出限为10.1～0.3 fmol.     

新型荧光衍生试剂用于尿样中痕量游离雌二醇和雌三醇的反相高效液相色谱-荧光检测和质谱定性

合成了新型高灵敏度的荧光标记试剂10-乙基吖啶酮-2-磺酰氯(EASC)。采用EASC柱前衍生化实现了雌二醇(E2)和雌三醇(E3)的反相高效液相色谱(RP-HPLC)-荧光分析及柱后质谱鉴定。试剂EASC比丹磺酰氯(DNS-Cl)具有更高的紫外、荧光和质谱检测灵敏度,其荧光发光强度是丹磺酰氯的1000倍以上。EASC与E2和E3在NaHCO3缓冲液(pH 10.5)中,于60 ℃下反应3 min即可获得稳定的荧光产物,最大激发波长(λex)和最大发射波长(λem)分别为270 nm和430 nm。所建立的方法具有良好的重现性,线性回归系数大于0.9990;检出限(S/N=3)为31 fmol 和40 fmol。对实际根田鼠尿样中的雌二醇和雌三醇含量进行了测定,结果令人满意。     

液相色谱法测定婴幼儿食品包装材料中的脂肪胺

采用新型气流吹扫-微注射器萃取( GP-MSE)技术,用酸化甲醇为提取溶剂,对食品包装材料中脂肪胺进行了提取和富集。以10-乙基-吖啶酮-2-磺酰氯( EASC)为荧光试剂,在60℃、pH 10的条件下,对脂肪胺进行柱前荧光衍生, Hypersil GOLD柱分离,荧光检测的激发波长(λex )和发射波长(λem )分别为262 nm和430 nm。12种脂肪胺检出限为0.4~0.6μg/kg,定量限为1.2~2.1μg/kg,在2.0~2000μg/L浓度范围内,线性相关系数均大于0.998。本方法具有快速、准确、灵敏的特点,用于婴幼儿食品包装材料分析,结果令人满意。     

脂肪胺荧光衍生物的高效液相色谱分离及质谱鉴定

采用新型荧光衍生试剂2-(9-吖啶酮)-乙酸(AAA)进行柱前衍生并经荧光检测对脂肪胺进行了高效液相色谱(HPLC)分离和在线质谱定性.衍生物荧光激发和发射波长为λex=404nm,λem=440nm.30℃下在乙腈溶剂中用N-乙基-N′-[(3-二甲氨基)丙基]碳二亚胺盐酸盐(EDC)做催化剂,衍生反应20min后获得稳定的荧光产物.在HypersilBDSC18(4.6mm×100mm,5μm)色谱柱上,采用梯度洗脱对12种脂肪胺衍生物进行了优化分离.采用大气压化学电离源(APCISource)正离子模式进行在线柱后质谱定性,实现了各种脂肪胺衍生物的快速、准确测定.该方法具有良好的重现性,多数脂肪胺的线性回归系数大于0.9996,检测限为12.09~25.52fmol.     

氮杂环荧光试剂2-(11H-苯[a]咔唑)乙基氯甲酸酯对胺类化合物标记及质谱鉴定

含氮类荧光试剂2-(11H-苯[a]咔唑)乙基氯甲酸酯(BCEC-Cl)经柱前衍生处理后,采用荧光检测及柱后在线质谱鉴定对食品中胺类化合物进行了测定。标记反应在pH9的硼酸缓冲液中进行,3min后获得稳定的荧光产物。衍生物于λex=279nm激发条件下产生强烈荧光,其发射波长在λem=380nm处。产物的分离在EclipseXDB-C8色谱柱(150mm×4.6mm,5μm)上进行,采用梯度洗脱对12种脂肪胺衍生物进行了优化分离。采用大气压化学电离源(APCISource)正离子模式进行在线的柱后质谱鉴定,实现了多种脂肪胺衍生物的快速、准确测定。建立的方法具有良好的重现性,回归系数大于0.9996,检出限为1.8~14fmol。     

柱前衍生-高效液相色谱分离测定及质谱鉴定脂肪胺

采用新型荧光衍生试剂2-(2-苯基-1-氢-菲[9,10-d]咪唑)-乙酸(PPIA)进行柱前衍生,经荧光检测实现了脂肪胺的高效液相色谱(HPLC)分离测定及柱后质谱鉴定。60℃下在乙腈溶剂中用N-乙基-N′-[(3-二甲氨基)丙基]碳二亚胺盐酸盐(EDC)做缩合剂,衍生反应15min可获得稳定的荧光产物。脂肪胺衍生物荧光检测波长为380nm(激发波长为260nm)。在EclipseXDB-C8色谱柱上,采用梯度洗脱对12种脂肪胺衍生物进行了优化分离,测定了造纸厂废水、大鼠端脑和酸奶中脂肪胺的含量。经柱后在线质谱大气压化学电离源(APCISource)正离子模式实现了各种脂肪胺衍生物的质谱鉴定,借助对活性中间体的质谱解析确定了衍生反应的反应机理。该方法具有良好的重现性和回收率,多数脂肪胺的线性回归系数大于0.9996;检出限为3.1~18fmol(S/N=3∶1)。     

荧光探针5-羰基咪唑苯并吖啶酮的合成及其LC-APCI-MS法测定胺

在不加任何催化剂条件下, 2-(12-苯并吖啶酮)-乙酸(BAAA)与N,N′-羰基双咪唑(CDI)缩合生成新型荧光探针5-羰基咪唑苯并吖啶酮(IEBA). IEBA在DMF溶剂中与胺类化合物形成的酰胺类衍生物不仅可发出强烈的荧光, 还具有较高的质谱离子化能力. 该衍生物在乙腈和甲醇-水溶液中的百分离子化δ值分别在0~57.32% 和0~62.14%范围内. 最大激发和发射波长λex/λem=272 nm/505 nm. 12种胺类衍生物的荧光检出限范围为0.15~0.50 ng/mL, 在线APCI-MS检出限范围为1.43~8.51 ng/mL.     

新型衍生化试剂雌激素衍生物的大气压化学电离质谱增敏研究

合成了用于酚羟基化合物衍生化试剂10-乙基吖啶酮-2-磺酰氯(EASC),EASC与雌二醇和雌三醇, 在pH=10.5 的NaHCO3缓冲溶液中、60 ℃下反应3 min可获得稳定的衍生产物. EASC与丹磺酰氯(Dansyl-Cl)相比:最大摩尔吸光系数之比UVEASC/UVDansyl-Cl = 6.67;荧光量子效率之比Φf(EASC)/Φf(Dansyl-Cl)=43,对雌二醇和雌三醇标记后的质谱离子流强度比为:ICEASC/ICDansyl-Cl = 4.98(雌二醇) 和 ICEASC/ICDansyl-Cl = 4.51(雌三醇).在LC-MS-APCI (MRM)模式下,能够高灵敏地实现雌二醇和雌三醇的快速质谱测定.建立的方法具有良好的重现性,回归系数大于0.9995;检出限分别为4.3 ng/L(雌二醇)和14 ng/L(雌三醇).对实际样品中藏羚羊粪便、根田鼠尿样和狼血清中痕量游离的雌二醇和雌三醇进行了测定,结果满意.     

2-(11H-苯[a]咔唑)-乙酸在脂肪胺的高效液相色谱分离及质谱鉴定中的应用

采用新型荧光衍生试剂2-(11H-苯[a]咔唑)-乙酸(BCA)进行柱前衍生并经荧光检测对脂肪胺进行高效液相色谱(HPLC)分离和质谱定性.衍生物荧光激发和发射波长为λex=285 nm,λem=384 nm.60 ℃下在乙腈溶剂中用N-乙基-N′-[(3-二甲氨基)丙基]碳二亚胺盐酸盐(EDC)作催化剂, 衍生反应15 min后获得稳定的荧光产物.在Hypersil BDS C18 (4.0 mm×200 mm, 10 μm) 色谱柱上, 采用梯度洗脱对12种脂肪胺衍生物进行了优化分离.采用大气压化学电离源(APCI Source)正离子模式进行质谱定性, 实现了各种脂肪胺衍生物的快速、准确测定.脂肪胺的线性回归系数不小于0.999 8 , 检出限(S/N=3)为5.73 ～31.3 fmol.     

氯甲酸2-(9-咔唑)乙基酯柱前衍生化HPLC法用于环境水中脂肪胺测定

利用一种新型的衍生化试剂氯甲酸2-(9-咔唑)乙基酯柱前衍生10种脂肪胺,建立了脂肪胺类化合物的梯度洗脱高效液相色谱分离分析方法,在紫外254nm条件下检测,线性检测范围为50-500μmol／L,检出(S／N=3)为9．5—25μmol／L;对海水及河水中脂肪胺的试验结果表明,建立的方法快速、灵敏度高,可以满足环境检测等方面的需要。     

Application of 10‐ethyl‐acridine‐3‐sulfonyl chloride for HPLC determination of aliphatic amines in environmental water using fluorescence and APCI‐MS

A simple, sensitive method for the determination of aliphatic amines based on a sulfonylation reaction using 10‐ethyl‐acridine‐3‐sulfonyl chloride (EASC) as pre‐column labeling reagent with fluorescence detection and APCI‐MS identification has been developed. The labeled derivatives exhibited high stability and were enough to be efficiently analyzed by HPLC with an excitation maximum at λ_ex 270 nm and an emission maximum at λ_em 430 nm. Identification of derivatives was carried out by online post‐column MS in positive‐ion mode. Comparing with the widely used 5‐dimethylaminonaphthalene‐1‐sulfonylchloride (Dansyl‐Cl), EASC‐amine derivatives not only exhibited high fluorescence but also exhibited excellent MS ionizable potential. Detection limits obtained from 0.10 pmol injection, at a S/N of 3, were 4.0–12.7 fmol. The mean intra‐ and inter‐assay precision for all aliphatic amine levels were <3.84 and 3.21%, respectively. Excellent linear responses were observed with coefficients of >0.9995.     

Fluorescence Probe of 10-Phenyl-acridone-2-sulfonyl Chloride and Its Application for Determination of Free Aliphatic Amines in Environmental Samples by HPLC with Fluorescence Detection and APCI-MS

A simple and sensitive method for the determination of free aliphatic amines using 10-phenyl-acridone-2-sulfonyl chloride (PASC) as a labeling reagent by high-performance liquid chromatography with fluorescence detection and online mass spectrometry identification (HPLC-FLD-MS) has been developed. Derivatization conditions including reagent concentration, buffer pH, reaction time and temperature were optimized. PASC reacted with aliphatic amines at 50 °C for 4 min in aqueous acetonitrile (ACN) in the presence of sodiumtetraborate–NaOH buffer (0.10 mol L⁻¹, pH 9.0) to give high yields of PASC-amine derivatives. Derivatives exhibited intense fluorescence with an excitation maximum at λ_ex 265 nm and an emission maximum at λ_em 418 nm. The separation of derivatives was performed by a reversed-phase Hypersil BDS C8 column in combination with a gradient elution. The identification of derivatives was carried out by online post-column mass spectrometry with atmospheric pressure chemical ionization (APCI) source in positive-ion detection mode. Excellent linear responses were observed with the correlation coefficients of larger than 0.9997, and detection limits (at a signal-to-noise of 3:1) were from 3.0 to 24.3 fmol. Comparing with 10-ethyl-acridine-2-sulfonyl chloride (EASC), PASC exhibited more intense fluorescence and ultraviolet absorbance. The proposed method is sensitive and reproducible for the determination of aliphatic amines from water and soil samples.

     

硫脲修饰法制备高发光性能CdTe量子点

通过巯基水解制备了具有优异荧光特性的碲化镉量子点. 详细研究前驱体镉离子与巯基丙酸(MPA)摩尔比、镉离子浓度等制备条件对大尺寸、高量子产率的亲水性碲化镉量子点光学性能的影响. 在不同的水热生长时间下, 可制备出荧光发射峰位于485-660 nm范围内的不同尺寸的碲化镉水溶性量子点, 荧光发射峰半高宽控制在40-75 nm之间, 量子点的最高量子产率(QY)达到了45%. 并利用硫脲缓慢水解和光解释放自由硫离子, 修饰碲化镉表面, 检测修饰后的量子点在12天内光学性能的变化情况. 通过考察硫脲用量对量子点修饰效果, 发现当n(CdTe)/n(thiourea)=1:4(量子点浓度以镉离子浓度计)时, 硫脲对发射峰为505 nm的碲化镉量子点修饰效果最为理想, 量子点荧光强度加强了5倍, 量子产率达到68.3%.     

6-Oxy-(N-succinimidyl acetate)-9-(2'-methoxycarbonyl)fluorescein as a new fluorescent labeling reagent for aliphatic amines in environmental and food samples using high-performance liquid chromatography

6-Oxy-(N-succinimidyl acetate)-9-(2'-methoxycarbonyl)fluorescein (SAMF), a new fluorescein-based amine-reactive fluorescent probe was well designed, synthesized and used as a pre-column derivatizing reagent for the determination of aliphatic amines in HPLC. It exhibited relatively pH-independent fluorescence (pH 4-9) and excellent photostability. The derivatization was performed at room temperature in 6min. On a C18 column, the derivatives of SAMF with eight aliphatic amines were baseline separated in 28 min with a mobile phase of methanol-water (57:43, v/v) containing 10 mmol l(-1) pH 5.0, H3Cit3-NaOH buffer. With fluorescent detection at lambda(ex)/lambda(em) = 484/516 nm, the detection limit could reach 2-320 fmol (signal-to-noise = 3), which was equivalent to or better than the detection limits obtained from other analytical methods of aliphatic amines. The proposed method has been applied to the determination of the aliphatic amines in environmental and food samples such as lake water, red wine, white wine, and cheese with satisfying recoveries varying from 95 to 106%.     

ZnO纳米棒薄膜的湿化学法制备及光致发光特性

在80 ℃水浴下, 采用简易的湿化学法在不导电玻璃基底上制备了ZnO纳米棒阵列, 利用X射线衍射仪(XRD)和场发射扫描电镜(FE-SEM)对样品的结构形貌进行了表征. 结果表明, 晶化30 min所得产物为六方纤锌矿相的ZnO纳米棒, 直径大约为80~90 nm. 为了分析不同的低温退火温度和退火气氛对其光致发光性能的影响, 研究了ZnO纳米棒薄膜在不同的后处理条件下的光致发光谱(PL). 实验结果表明, 在O₂气氛下于450 ℃退火1 h后, ZnO纳米棒薄膜的红光发射(约650 nm)强度相对在空气和5%H₂/95%N₂气氛下退火的样品变得更强, 而且该样品的激发波长范围(200~370 nm)与近紫外发光二极管(LEDs)的发射波长范围(350~420 nm)匹配得很好.     

用双波长分光光度法测定稀土和钪在其混合物中的含量

氨基C酸偶氮氯膦曾用于稀土胶溶络合物体系[1]。该显色剂在醋酸介质中与各稀土元素及钪形成稳定的络合物。这两种络合物的吸收光谱有明显的差异,利用这些差异,我们应用双波长分光光度法直接分别测定了稀土和钪在其混合物中的含量。方法简便、快速。     

食品中苏丹红Ⅰ和辣椒红的表面增强拉曼散射(SERS)光谱与激发-发射矩阵荧光光谱鉴别

利用表面增强拉曼散射(SERS)光谱及激发-发射矩阵(EEM)荧光光谱对食品中非法添加剂苏丹红Ⅰ和合法食品添加剂辣椒红进行了定性分析和检测. SERS光谱结果表明, 苏丹红Ⅰ在低波数区域分子的扭转振动信号增强比较明显; 而辣椒红在1521和1158 cm^-1处拉曼信号增强效果比较明显; EEM荧光光谱结果表明, 苏丹红Ⅰ的乙醇溶液在P₁(λ_ex=285 nm, λ_em=345 nm)和P₂(λ_ex= 335 nm, λ_em=548 nm)处有2个明显的荧光特征峰; 而辣椒红的乙醇溶液有3个特征荧光峰, 分别为P₁(λ_ex=545 nm, λ_em=580 nm), P₂(λ_ex=560 nm, λ_em=665 nm)和P₃(λ_ex=608 nm, λ_em=672 nm).