枸杞中烟酸提取方法研究

建立了超声、微波辅助酸解法两种样品前处理法,并结合紫外可见分光光度计测定了枸杞中烟酸的含量。考察了影响两种前处理方法的因素包括超声和微波提取功率、料液比、提取温度、提取时间。结果表明,方法的线性范围为5.0¹00.0μg/m L,相关系数r=0.998 3;日内和日间重现性分别为2.1%和6.8%。并将两种方法成功应用于3种市售枸杞中烟酸含量的测定,加标回收率为87.3%100.0μg/m L,相关系数r=0.998 3;日内和日间重现性分别为2.1%和6.8%。并将两种方法成功应用于3种市售枸杞中烟酸含量的测定,加标回收率为87.3%¹09.6%,相对标准偏差为2.01%109.6%,相对标准偏差为2.01%⁹.25%。     

火焰原子吸收测定再加工茶中金属元素的研究

运用火焰原子吸收光谱法测定再加工茶(荔枝红茶与茉莉花茶)中的K、Ca、Mn、Fe和Zn五种金属元素的含量,同时对干法和湿法两种不同消解方法进行了比较和准确度的测试。通过校准曲线法测定,采用干法消解的两种茶叶样品中的金属含量略高于湿法消解,两种方法测定的加标回收率在92.31%～106.38%之间,同时RSD均小于5%,该实验方法具有准确度高,可靠性大等优点可满足分析要求。     

石墨消解-火焰原子吸收分光光度法测定苹果中五种微量元素

采用石墨消解-火焰原子吸收分光光度法来测定红蛇果和红富士两种苹果中的Ca、Mg、Zn、Cu、Mn五种微量元素的含量。结果表明,两种品种的苹果中都含有较丰富的Ca、Mg元素,而Zn、Cu、Mn元素的含量则较少,两种苹果中微量元素的含量差别不大。用该方法测得红蛇果和红富士中Ca、Mg、Zn、Cu、Mn的检出限0.071,0.001 8,0.004 2,0.000 96,0.004 2μg/m L;回收率分别是91.42%,93.38%,90.84%,97.47%,93.24%;精密度分别是1.3%,1.7%,1.8%,1.0%,1.4%。此方法适用于苹果中微量元素的测量。     

石墨消解-火焰原子吸收分光光度法测定苹果中五种微量元素

采用石墨消解-火焰原子吸收分光光度法来测定红蛇果和红富士两种苹果中的Ca、Mg、Zn、Cu、Mn五种微量元素的含量。结果表明,两种品种的苹果中都含有较丰富的Ca、Mg元素,而Zn、Cu、Mn元素的含量则较少,两种苹果中微量元素的含量差别不大。用该方法测得红蛇果和红富士中Ca、Mg、Zn、Cu、Mn的检出限0.071,0.001 8,0.004 2,0.000 96,0.004 2μg/m L;回收率分别是91.42%,93.38%,90.84%,97.47%,93.24%;精密度分别是1.3%,1.7%,1.8%,1.0%,1.4%。此方法适用于苹果中微量元素的测量。     

枸杞中烟酸提取方法研究

建立了超声、微波辅助酸解法两种样品前处理法,并结合紫外可见分光光度计测定了枸杞中烟酸的含量。考察了影响两种前处理方法的因素包括超声和微波提取功率、料液比、提取温度、提取时间。结果表明,方法的线性范围为5.0~100.0μg/m L,相关系数r=0.998 3;日内和日间重现性分别为2.1%和6.8%。并将两种方法成功应用于3种市售枸杞中烟酸含量的测定,加标回收率为87.3%~109.6%,相对标准偏差为2.01%~9.25%。     

火焰原子吸收光谱法测定尿素中铁

建立了火焰原子吸收光谱法测定尿素中铁含量的方法,并与邻菲啰啉分光光度法进行比较,分别用两种方法进行了样品、空白值、加标回收率实验。结果表明,两种方法的检出限均为0.02 mg/L,精密度为2.2%和2.4%,加标回收率分别为96%~104%和96%~103%,其结果令人满意。     

电感耦合等离子体发射光谱法测定天然滑子蘑中磷的含量

本文采用灰化法,湿法两种方法处理样品,ICP-AES法测定天然滑子蘑中磷元素的含量。并对两种方法进行比较,两种方法并没有显著性的差异,相对标准偏差为1.03%,3.87%。平均回收率为95.3%,103.6%。     

吹扫捕集-气相色谱法和顶空-气相色谱法测定水中乙醛、丙烯醛和丙烯腈的比较

建立了吹扫捕集-气相色谱法和顶空-气相色谱法测定水中乙醛、丙烯醛和丙烯腈的分析方法。本文分别对两种方法的谱图、分离度、线性范围、方法检出限、精密度和加标回收率等进行了比较。吹扫捕集-气相色谱法的精密度范围为2.3%～4.5%;加标回收率范围为90.1%～109.0%。顶空-气相色谱法的精密度范围为1.4%～3.8%;加标回收率范围为90.6%～106.2%。两种方法均能完全分离各目标化合物,具有良好的线性,相关系数均大于0.999,吹扫捕集-气相色谱法的检出限更低于顶空-气相色谱法。结果表明,两种方法均能准确测定水中乙醛、丙烯醛和丙烯腈,吹扫捕集-气相色谱法更适合低浓度地表水和地下水的分析,顶空气相色谱法更适合高浓度、基体复杂废水的分析。     

宫外孕Ⅱ号加味与氨甲碟呤(MTX)中西医两种药物保守治疗输卵管妊娠的疗效观察

目的评价两种不同方法保守治疗输卵管妊娠的疗效。方法将患者随机分A、B两组,治疗2周后评价疗效。结果两组治愈率分别为:A组42.11%,B组66.67%。结论两种药物治疗无明显差异。     

高效液相色谱法和气相色谱质谱联用法测定炼油碱性污水中酚类物质的含量

建立了高效液相色谱法和气相色谱质谱联用法测定炼油碱性污水中的酚类物质含量的两种方法。对同一样品,用高效液相色谱分析其含量,其中苯酚含量为18.49%,对甲酚含量为8.12%,邻甲酚含量为1.80%,用气质联用法测得苯酚含量为18.40%,对、间甲酚含量为9.09%,邻甲酚含量为1.91%。两种方法对三种主要的酚类物质的测定结果相近,都有很好的精密度和准确度。     

An evaluation of supercritical fluid extraction as an analytical tool to determine fat in canola,flax, solin,and mustard

Supercritical fluid extraction (SFE) with carbon dioxide was used to extract oil from soft oilseeds (flax, solin, canola, and mustard). Oil content determinations from the SFE method AOCS Am 3–96, with and without ethanol as a modifier, were compared to results obtained with an exhaustive extraction using petroleum ether (FOSFA as in AOCS Am 2–93). Without the modifier, oil recoveries using SFE were 10 to 15% lower than oil contents by the FOSFA method for the flax and canola samples. For mustard, the oil recoveries by SFE were about 20 to 30% lower than oil contents by the FOSFA method. In the presence of the modifier, oil recoveries for flax and canola were about 3% lower than the FOSFA recoveries. Varying the time, temperature, and amount of modifier (ethanol) showed that recoveries increased with time, pressure, temperature, and amount of modifier independently of the oilseeds tested. Kinetics of the SFE extraction showed that the oil recoveries increased with the extraction time and reached a plateau after 60 min. Multiple extractions (2×30 min), however, gave better recoveries than a single extraction for the same amount of time (60 min). The best results were obtained using multiple extractions without modifier or a combination of multiple extractions first without and then with 15% modifier. Under these last two conditions, oil recoveries were close to 100% for flax, solin, and canola, but mustard oil recoveries were still 10% lower than recoveries using the FOSFA method. Mustard samples gave the lowest oil recovery from SFE when compared to FOSFA method recoveries whatever conditions were tested, suggesting a matrix effect on the oil recovery. The acyl lipid content of the various extracts was studied using the sum of all FA expressed as TAG as a measure of acyl lipid extraction. The acyl lipid contents of the extracts were close to 100% when no modifier was used during the SFE. In the presence of modifier, the acyl lipid contents of the extracts were 10 to 15% lower than the results obtained without modifier. The amount of acyl lipid in the extract decreased as the quantity of modifier increased. This suggests that increasing the ethanol modifier increased the amount of polar compounds extracted without significantly increasing the total amount of lipids. The FA profiles were constant throughout the various extraction procedures.     

Enhanced oil recovery using carboxylate surfactant systems

Oil displacement tests in water wet Berea sandstone cores containing residual crude oil flooded with water have shown that high tertiary oil recoveries can be obtained using the sodium salts of readily available carboxylic acids. Using a 10% pore volume surfactant slug containing 3.0% sodium isostearate and 3.0% isopentyl alcohol followed by a polyacrylamide mobility buffer resulted in a 92% tertiary oil recovery, which compares well with recoveries using petroleum solfonates. Oil recoveries were highly dependent on pH and added base. Aliphatic C18 carboxylates gave higher recoveries at lower pH using sodium bicarbonate as the added base (pH 8.5) rather than sodium hydroxide, sodium carbonate or sodium orthosilicate (pH 11–13). In contrast, aromatic carboxylates e.g., sodium p-(1-pentylnonyl)benzoate, gave higher recoveries at higher pH using sodium carbonate rather than sodium bicarbonate. Carboxylates with branched alkyl groups, e.g., isostearate, gave higher tertiary oil recoveries than unbranched carboxylates, e.g., oleate or stearate. Low cost tall oils and tall-oil fatty acids, when neutralized with base, gave oil recoveries of 60–80%. Carboxylates were found to give good oil recoveries even when significant amounts of calcium ion were present.     

二氯甲烷提取小麦中吡虫啉的可行性研究

对甲醇提取的关键步骤——分液进行了优化,比较了甲醇和二氯甲烷提取小麦中吡虫啉的添加回收率及提取效果的差异。结果表明,分液萃取静置时间影响甲醇对吡虫林的提取,以30 min最佳,此时添加回收率为99.22%～100.56%:二氯甲烷提取不需分液萃取静置,添加回收率为100.25%～101.93%,与甲醇提取优化后的添加回收率相当,可用于提取小麦中的吡虫啉。因二氯甲烷提取较甲醇提取操作步骤简便,提取杂质少,样品测定周期短,测定成本低,故二氯甲烷比甲醇更适合用于小麦样品大批量的测定。     

Synthesis of 100-gram quantities of highly purified mixed acid triglycerides

Monopalmitin, mono-olein, and monostearin have been synthesized in quantities of up to 100 grams with recoveries ranging from. 80%-85%. The monoglycerides were reacted with a 0.5 molar excess of pyridine and fatty acid chloride to produce 1, 3,-diglycerides. The recoveries ranged from 60%-70% and, in addition, considerable amounts of triglyceride were obtained from this reaction. Partial glycerides were converted to 100-gram batches of triglyceride in a similar manner with recoveries ranging from 80%-90%. Purification of the partial glycerides was achieved by crystallization. In addition to this technique, certain triglycerides were purified by elution through a column of alumina. Purity of the glycerides, as determined by TLC, G-LC, and pancreatic lipolysis, was estimated to be at least 99%. 1 Scientific contribution No. 243.     

SPE-GC/MS同时测定蔬菜中除虫脲和灭幼脲残留

采用乙腈提取,经石墨化炭黑氨基复合柱净化,GC/MS测定,采用内标法定量,建立了蔬菜中除虫脲和灭幼脲残留的SPE-GC/MS同时测定方法.除虫脲的添加质量分数为2.0、1.0、0.4、0.08 mg/kg,方法平均回收率为98.5%、101.0%、105.0%、100.1%,变异系数为3.90%～7.75%,检出限为0.008 mg/kg;灭幼脲添加质量分数为5.0、3.0、1.0、0.08 mg/kg,方法平均回收率为90.8%、94.9%、99.2%、94.4%,变异系数为6.18%～8.28%,检出限0.004 mg/kg.     

中药植物战骨总黄酮的提取

用传统索氏提取法及现代提取方法——微波萃取法、超声波萃取法、内部汽化法4种不同的提取方法对战骨中的总黄酮进行了提取工艺研究。采用上述4种方法对战骨中总黄酮进行提取,并进行了后3种方法的L9(34)正交设计性实验。测定了以上4种方法的战骨提取液的总黄酮含量及回收率,并将后3种方法与索氏提取法进行比较。结果表明,微波萃取法、超声波萃取法、内部汽化法的最优方案的收率分别为2.07%,1.90%,1.78%,平均回收率分别为100.60%,105.12%,99.92%,相对标准偏差分别为1.40%,1.47%,1.16%。索氏提取法提取的收率为0.95%。现代方法的收率均高于传统索氏提取法。     

Solid Phase Extraction for Determination of Polycyclic Aromatic Hydrocarbons from Atmospheric Wet and Dry Deposition Samples

Solid phase extraction with C-18 sorbent tubes was employed for extraction and preconcentration of trace level (ng/l) of polycyclic aromatic hydrocarbons (PAHs) from water samples obtained by collecting wet and dry atmospheric deposition. Recoveries of spiked PAHs from 0.2 to 10.0 l water samples ranged from 60% to 90%. Five deuterated PAHs (naphthalene- d 8 , acenaphthene- d 10 , anthracene- d 10 , chrysene- d 12 , and perylene- d 12 ) were added to the samples as surrogates. The recoveries of surrogates were in the same range as the spiked PAHs. The recoveries of surrogates were used to estimate the recoveries of ambient PAHs with a similar ring structure. Factors that contributed to the relatively low recoveries include breakthrough of the sorbates, adsorption on the container surface, and degradation in water during storage.     

气相色谱法测定环境空气中的微量异戊烯和异戊二烯

建立了环境空气中异戊烯、异戊二烯的活性炭吸附,二硫化碳解吸气相色谱法。用DB-1毛细管柱分离,FID进行检测。该方法异戊烯的回收率为87.6%~105.2%,RSD为2.1%~8.2%,异戊二烯的回收率为86.1%~105.1%,RSD为4.2%~8.5%。当采样体积为2 L时,异戊烯最低检测限为0.04 mg/m3,异戊二烯最低检测限为0.06 mg/m3。     

红外光谱法测定生物质燃料中全硫的研究

建立红外光谱法测定生物质燃料中全硫含量的方法,采用标准样品校正仪器,拟合校正曲线,研究了该方法的准确度和精密度。结果表明,全硫含量在0%~4.45%范围内,测量值和实际值硫含量线性关系良好,用标准加入法进行回收率实验对方法的准确度进行考察,相对标准偏差为0.76%~1.52%,加标回收率为99.44%~99.89%。与其他检测方法比较,该方法操作简单,检测时间短,自动化程度高。     

氟虫腈的色谱分析方法

对氟虫腈的色谱分析方法进行了系统研究。高效液相色谱法选用紫外检测器和C18反相柱，采用外标法对市售氟虫腈产品进行定性定量分析，方法的相对标准偏差为0．42％，添加回收率为100．5％～104．3％。气相色谱法采用OV-17色谱柱和火焰离子化检测器，选用邻苯二甲酸二丁酯为内标物对市售氟虫腈样品进行定性定量分析，方法的相对标准偏差为1．60％，添加回收率为98．1％～100．8％。