长叶水麻挥发性化学成分研究

长叶水麻(Debregeasia longifolia (Burm.f.) Wedd.)是荨麻科植物,果可食,根入药,除风湿。本文采用毛细管气相色谱_质谱联用法对长叶水麻挥发性化学成分进行了研究,经毛细管色谱分离出108个峰,共确认了其中83种成分。用气相色谱面积归一化法测定了各成分的相对百分含量,分析鉴定结果表明,长叶水麻挥发油主要化学成分为丁基化羟基甲苯、十五烷、邻苯二甲酸二丁酯、2,6-二甲基奈、癸酸乙酯、十八烷、丁二酸二乙酯、3,7-二甲基-1,6辛二烯-3-酮等,化合物类型以烃、脂肪酸和酯、醇、酮、芳香和芳香杂环化合物为主。     

异叶青兰挥发性化学成分研究

采用毛细管气相色谱－质谱联用法对异叶青兰挥发性化学成分进行了研究,经毛细管色谱分离出１８４多个峰,共确认了其中１５４种成分,所鉴定化合物的含量占全油的８３．５２％。用气相色谱面积归一化法测定了各成分的相对百分含量,其主要化学成分为４－甲基噻唑、６,６－二甲基－二环「３,３,１」－庚－２－烯－２－甲醇,４－（１－甲基乙基）－苯甲醇、十六酸乙酯等。     

中国珍稀植物明党参嫩茎叶挥发油化学成分研究

采用毛细管气相色谱－质谱－计算机联用技术对明党参嫩茎叶挥发油的化学成分进行研究,从挥发油中鉴定出２７种成分,占总油量的９７．５０２％,其主要成分是Ｍａｎｇ牛儿醇乙酸酯（４６．６３６％）,明党参炔（１１．４８３％）,β－金合欢烯（１０．９８６％为阐明明党参特征性化学及茎叶的一切利用提供了依据。     

关于油樟叶芳香油化学成分的研究

用毛细管气相色谱——质谱——计算机联用技术、毛细管气相色谱保留指数和毛细管标准品叠加法分析了油樟Cinnamomum lonoepaniculatum叶芳香油的化学成分。从分离出来的49个色谱峰中鉴定出了28个成分,其中主要成分是1,8—桉叶脑(58.55%)、α—萜品醇(15.43%)、香桧烯(14.16%)等。     

三花莸挥发油化学成分的研究

用自制的水蒸气蒸馏－溶液萃取装置从马鞭草科莸属Ｃａｒｙｏｐｔｅｒｉｓ Ｂｕｎｇｅ植物三花莸Ｃ．ｔｅｒｎｉｆｌｏｒａ Ｍａｘｉｍ．中提取挥发油,含量为１．００３％,用毛细管气相色谱－质普法对其挥发油的化学成分进行了研究,含量为分离出５０多个组分,质谱鉴定了２５个成分,占总色谱峰面积的６３．７８％。三花莸挥发油 的主要组分为α－柠檬烯（３７．４０％）,（＋）－顺－桧醇（２６．９０％）,还含有α－蒎烯,     

福建产小鱼仙草挥发油的含量及其化学成分的研究

应用气相色谱－质谱－计算机联用系统对小鱼仙草（Mosla dianthera Maxim),挥发油的化学成分进行研究,以SE－54石英毛细管柱分离出43个峰,用GC／MS鉴定出39个成分,其主要成分为百里香酚（37．15％）,香荆芥酚（14．85％）,丁香烯（5．75％）,芳樟醇（5．40％）,檀香烯（4．12％）,律草烯（3．61％）,香桧醇（2．87％）等,占总挥发油的98．40％,又应用气相色谱归一化法计算了各化学成分含量。     

藏药短管兔耳草脂溶性化学成分的GC-MS分析

采用毛细管色谱-质谱联用技术对青海省短管兔耳草石油醚浸提物的化学成分进行了分析,共分离出42个峰,鉴定出32种不同化合物。用气相色谱面积归一化法测定了各化学成分的相对含量,主要成分有亚油酸（39．037％）、正三十一烷（10．827％）、正二十九烷（6．683％）、棕榈酸（5．234％）、正十八烷（2．485％）、γ-谷甾醇（2．264％）等。     

黄荆挥发油化学成分的研究

采用气相色谱－质谱联用仪对产于秦岭略阳的黄荆叶的挥发油成分进行了分析鉴定,共确定出了３５种成分。主要成分为石竹烯（３３．０１％）、桉树脑（１３．３０％）、β－水芹烯（１３．２３）、别－香树烯（６．５８％）和β－法呢烯（５．５６％）。     

中国特有的反式－甲基异丁香酚新资源植物

中国特有植物银木和阔叶樟集中产于湖北西南部山区,资源丰富,其鲜叶经水蒸汽蒸馏获得重油（比重大于水）,分别使用毛细管气相色谱／质谱／计算机联用方法进行化学成分分析。结果表明：这两种精油的主成分均为反式－甲基异丁香酚,含量分别高达85．71％和94．04％。     

中国特有的反式－甲基异丁香酚新资源植物

中国特有植物银木和阔叶樟集中产于湖北西南部山区,资源丰富,其鲜叶经水蒸汽蒸馏获得重油（比重大于水）,分别使用毛细管气相色谱／质谱／计算机联用方法进行化学成分分析。结果表明：这两种精油的主成分均为反式－甲基异丁香酚,含量分别高达85．71％和94．04％。     

Simultaneous determination of 19 intracellular nucleotides and nucleotide sugars in Chinese Hamster ovary cells by capillary electrophoresis

Twelve nucleotides and seven nucleotide sugars in Chinese Hamster ovary (CHO) cells were determined by capillary electrophoresis (CE). The CE operating conditions of buffer pH value, ion strength, capillary temperature, polymer additive and cell extraction method were investigated. Optimum separation was achieved with 40 mM sodium tetraborate buffer (pH 9.5) containing 1% (w/v) polyethylene glycol (PEG) at a capillary temperature of 22 degrees C. Acetonitrile and chloroform were used for intracellular extraction. This method can be used to monitor intracellular carbohydrate metabolism.     

Determination of local variation of the thickness of the capillary basement membrane of the human placenta at term by a morphometric method

Material was taken from exactly determined sites on five placentas to determine local variation of the thickness of the capillary basement membrane in the normal human placenta at term. The thickness of the capillary basement membrane was determined in electron micrographs by a morphometric method and the resultant values were processed statistically. The results and the method are both discussed.     

Analysis of ibuprofen in serum by capillary electrophoresis

A rapid method for analysis of the analgesic drug ibuprofen in serum by capillary zone electrophoresis in a borate buffer 160 mmol/l pH 8.5 is described. The method involves deproteinization with acetonitrile to remove serum proteins followed by direct injection on the capillary. The recoveries of standards added to the serum were 84–92%. The method is suited for analysis of samples with concentrations >10 mg/l. Many other analgesics such as ketoprofen, daypro and salicylates can also be determined by this method.     

Pitfalls of venous occlusion method for determination of capillary pressure in humans

We tested the method of estimating capillary pressure from venous pressure transients obtained after sudden venous clamping in a hydrodynamic model. The basic principles were confirmed in the model, but it was found that when occlusion was caused over a relatively wide distance or in a predistended vessel, capillary pressure was overrated. This problem was due to volume backflow from the occlusion site, since it could be eliminated by placing a one-way valve upstream from the occlusion site. Upstream from the valve, the venous pressure transient accurately followed capillary pressure. Downstream, however, the reading of capillary pressure was impaired by the backflow volume squeezed between valve and occlusion clamp, which caused an immediate large pressure elevation. We also tested the method recently advanced to estimate capillary pressure in humans from venous pressure curves obtained after rapid venous occlusion with an air-filled compression cuff. With the cuff around the upper arm, venous pressure was recorded at different levels along the forearm. The tracings obtained from the dorsum of the hand and halfway along the forearm did not show the initial rapid upstrokes that might indicate the capillary pressure. Tracings obtained slightly below or above the cubital fossa were similar to those seen downstream from the one-way valve in the model. Extrapolation to zero-time, using the distally recorded curves as a template, yielded values equal to venous pressure. We conclude that although the problem of backflow can be circumvented by pressure recording distal from venous valves, the method of venous occlusion by a circular upper-arm cuff may not be appropriate to estimate capillary pressure in humans.     

Determination of urinary succinylacetone by capillary electrophoresis for the diagnosis of tyrosinemia type I

The presence of succinylacetone in urine or blood or amniotic fluid is pathognomonic of an inherited metabolic disorder, named tyrosinemia type I. We developed a capillary electrophoretic method for the fast analysis of succinylacetone in urine samples. The separation was performed at reversed polarity mode using either a cationic surfactant as the buffer additive, or a capillary coated with a positively charged polyelectrolyte. Under these conditions, urine samples were directly injected to the capillary without any pretreatment step. The utility of the method was demonstrated by the identification of succinyacetone in urine from patients with hereditary tyrosinemia type I. For all patients, diagnostic peaks at the expected migration times were detected. The developed method is rapid, simple, inexpensive, and suitable for the determination of succinylacetone in clinical urine samples.     

Optimization and validation of analytical conditions for bovine serum albumin using capillary electrophoresis.

A quick and reproducible capillary electrophoresis method was optimized and validated for the assay of bovine serum albumin (BSA). The effects of various parameters such as pH of buffer, concentration of buffer, capillary dimensions, use of coated capillaries, and additives such as surfactants and protein solubilizers were evaluated. The capillary coatings or additives did not give any advantage in reducing the surface adsorption of BSA on the capillary walls. The optimized conditions include use of borate buffer, pH 8.5 having a concentration of 150 mM in a 27 cm capillary with an aperture window of 100 x 200 microns for detection. The optimized method for the detection of BSA was validated. The interday and intraday coefficient of variation was not greater than 7.59% at BSA concentrations of 25-1000 micrograms/ml. The method developed was reproducible and accurate.     

Rapid quantification of DNA methylation through dNMP analysis following bisulfite-PCR

We report a novel method for rapid quantification of the degree of DNA methylation of a specific gene. Our method combined bisulfite-mediated PCR and quantification of deoxyribonucleoside monophosphate (dNMP) contents in the PCR product through capillary electrophoresis. A specific bisulfite-PCR product was enzymatically hydrolyzed to dNMP monomers which were quantitatively analyzed through subsequent capillary electrophoresis. PCR following bisulfite treatment converts unmethylated cytosines to thymines while leaving methyl-cytosines unchanged. Then the ratio of cytosine to thymine determined by capillary electrophoresis represents the ratio of methyl-cytosine to cytosine in genomic locus of interest. Pure oligonucleotides with known sequences were processed in parallel as standards for normalization of dNMP peaks in capillary electrophoresis. Sources of quantification uncertainty such as carryovers of dNTPs or primers and incomplete hydrolysis were examined and ruled out. When the method was applied to samples with known methylation levels (by bisulfite-mediated sequencing) as a validation, deviations were within ±5%. After bisulfite-PCR, the analytical procedure can be completed within 1.5 h.     

An enzyme immobilized microassay in capillary electrophoresis for characterization and inhibition studies of alkaline phosphatases

A simple and fast dynamically coated capillary electrophoretic method was developed for the characterization and inhibition studies of alkaline phosphatases (EC 3.1.3.1). An inside capillary enzymatic reaction was performed, and hydrolysis of the substrate 4-nitrophenylphosphate to 4-nitrophenol was measured. Fused-silica capillary surface was dynamically modified with polycationic polybrene coating. By reversal of the electroosmotic flow (EOF), analysis time was reduced up to 3 min as the anionic analytes were migrated in the same direction as the EOF. Furthermore, the sensitivity of the method was increased using electroinjection through high-field amplified injection. The baseline separation of 4-nitrophenylphosphate and 4-nitrophenol was achieved by employing 50 mM sodium phosphate as the running buffer (pH 8.5), 0.0025% polybrene, and a constant voltage of −15 kV, and the products were detected at 322 nm. Under the optimized conditions, a good separation with high efficiency was achieved. The new method was applied to study enzyme kinetics and inhibitor screening. K_m and K_i values obtained with the new CE method were compared well with the standard spectrophotometric method. Dynamic coating of fused-silica capillary gave fast and reproducible separation of substrate and product. The method can be easily optimized for inhibition studies of other isozymes.     

海洋真菌多不饱和脂肪酸的快速检测

从海水中分离了一种产EPA和DHA的真菌,并建立了微生物油脂的快速提取、甲酯化及其多不饱和脂肪酸的含量的气相色谱测定方法。结果表明：采用CHCl3-KOH-CH3OH一步提取甲酯化适合于产多不饱和脂肪酸菌株的快速检测。对其油脂的提取,采用湿菌丝魏氏盐酸水解法较为合适;并用KOH－CH3OH法对所得油脂进行了甲酯化。最后,运用毛细管气相色谱采用外标法测定了甲酯化样品中多不饱和脂肪酸的含量,其油脂中EPA和DHA的含量分别为7.32％和7.58％。