高效液相色谱法测定水产品中ATP关联化合物

建立了水产品中三磷酸腺苷(ATP)、二磷酸腺苷(ADP)、腺苷酸(AMP)、肌苷酸(IMP)、次黄嘌呤核苷(HxR)和次黄嘌呤(Hx)6种ATP关联化合物的高效液相色谱检测方法。样品中的ATP关联物经高氯酸提取并用氢氧化钠调节pH值至6.0-6.4后,以AQ-C18(250 mm×4.6 mm,5μm)柱为分析柱,0.02 mol/L KH2PO41-0.02 mol/L K2HPO4(V/V=1/1)的缓冲液为流动相进行洗脱,在254 nm波长下用高效液相色谱进行检测,外标法定量。研究表明,ATP、ADP、AMP、IMP和HxR线性范围为0.2-40.0μg/ml,Hx线性范围为0.1-20.0μg/ml,相关系数均大于0.999 0;ATP、ADP、AMP、IMP和HxR检出限为5.00 mg/kg,Hx检出限为2.5 mg/kg(S/N=3);对真鲷、鱼师鱼、鲑鱼、凡纳滨对虾和梭子蟹5种水产品进行3个浓度水平的加标实验,回收率在85.5%-105%之间,相对标准偏差(RSD)小于12.9%。实验结果表明,该方法简便、准确,适合于水产品中ATP关联物的测定。     

ICS-90型离子色谱测定饮用水中硫酸根离子的不确定度分析

科学准确地测定硫酸根高子,对于评价饮用水水质好坏,保障人体健康有重要意义.本文依据CNAS-GL06《化学分析中不确定度的评估指南》,通过采样分析、试验,对离子色谱法测定水中硫酸根离子的不确定度进行了评定.结果表明,水中硫酸根离子浓度为49.683 mg/L,扩展不确定度为1.364 mg/L,不确定度的最大来源是拟合...     

柱前衍生-高效液相色谱法测定浒苔多糖的组成

研究了浒苔多糖样品经三氟乙酸完全水解而无损失的最适条件,并且在优化流动相洗脱程序等色谱条件的基础上,建立了1-苯基-3-甲基-5-吡唑啉酮(PMP)柱前衍生-高效液相色谱法分析浒苔多糖的单糖组成及含量的方法。该方法采用配备紫外检测器的高效液相色谱仪,在250 nm波长下进行测定,外标法定量。结果表明,在此条件下,8种单糖能够良好分离,各单糖在1-100μg/ml范围内具有良好的线性关系,相关系数r≥0.999,回收率在76.0%-108%之间,相对标准偏差RSD10%。采用该方法对浒苔多糖样品进行组成及含量分析,发现无论样品原料为何种浒苔,浒苔多糖均以鼠李糖为主,同时还含有葡萄糖醛酸、葡萄糖、木糖、半乳糖以及少量的甘露糖、半乳糖醛酸和岩藻糖。     

大豆异黄酮对奶牛乳腺上皮细胞增殖及泌乳性能的影响

通过体外细胞培养方法研究大豆异黄酮对奶牛乳腺上皮细胞增殖及泌乳性能的影响。取对数生长期的奶牛乳腺上皮细胞,用无血清培养基培养24 h,使细胞同步化后分组试验。试验分空白对照组(0 mg/L大豆异黄酮)和添加不同浓度大豆异黄酮(1、10、100、1000 mg/L)组,培养48 h后,采用CASY 细胞计数仪检测细胞增殖能力与活力,高效液相色谱检测β-酪蛋白和乳糖,甘油三酯检测试剂盒检测甘油三酯的分泌情况。结果表明,与对照组相比,10、100、1000 mg/L大豆异黄酮组奶牛乳腺上皮细胞的增殖能力与活力显著增强(P<0.05);细胞分泌β-酪蛋白、乳糖和甘油三酯的能力也显著提高(P<0.05)。因此,添加10、100、1000 mg/L大豆异黄酮均能促进奶牛乳腺上皮细胞增殖及提高其泌乳性能,且呈一定的浓度依赖性。     

二十碳五烯酸甲酯标准样品的研制

以深海鱼油为基础原料,将其皂化水解为游离脂肪酸,经尿素—甲醇包合粗分离后,以硫酸—甲醇甲酯化,再经硝酸银—硅胶柱层析精分离,得到高纯度的二十碳五烯酸甲酯标准物质。经定值检测,确定其化合物纯度≥98%。     

大麦虫（Zophobsmorio L.）幼虫生长过程中维生素E含量变化的研究

大麦虫是一种高含油的新型资源昆虫。利用高效液相色谱法测定了大麦虫幼虫体内维生素E的含量,并对其随日龄、体重、体长的变化趋势进行了分析。结果表明：大麦虫幼虫含有丰富的α 维生素E和少量的δ、β、γ 维生素E,α 维生素E的变幅在168.64~264.57 mg/kg之间。在45~87日龄期间,大麦虫幼虫的日龄、体重、体长三者之间有极显著的线性相关（R2≥0.964,P＜0.01）。α 维生素E含量与这三项指标有极显著的二项式曲线相关,其与体长相关性最高（R2=0.640,P＜0.01）,当体长达5.1 cm时,幼虫体内α 维生素E含量最高,是生产高维生素E产品结束养殖的最佳时间。     

高效液相色谱法测定花生仁中甲咪唑烟酸残留

目前花生仁中甲咪唑烟酸残留量的检测是参考国标中茶叶农残的方法,花生仁基质含有大量的油脂和蛋白质,这与茶叶基质有显著区别,且该方法只能定性。本文建立了一种高效液相色谱法定量检测花生仁中甲咪唑烟酸残留量的方法。花生仁样品采用乙腈溶液提取后再经过除脂净化处理,以乙腈:0.02mol/L磷酸二氢钾缓冲液(加入0.1%的三乙胺,磷酸调pH3.0)体积比1:3作为流动相进行高效液相色谱紫外检测器分析。结果表明:甲咪唑烟酸标准在0~1.2mg/L范围内线性关系良好(R2=0.9999),检出限为7μg/kg;加标回收率为91.1%~98.9%;精密度、重复性、稳定性都较好。该方法操作简便、分离度好、结果准确,能很好地满足花生仁中甲咪唑烟酸残留量检测的要求。     

Study on Quality Standards of Children Antipyretic Lotion

[Objectives]To establish suitable quality standards of children antipyretic lotion.[Methods]Qualitative identification was performed for Paederia scandens and A...     

Characterization of humus-protease complexes extracted from soil

Pyrophosphate (140 mM, pH 7.1) extracts of two arable soils and one pasture soil were ultrafiltrated separating the extracted material into three fractions: A_I with nominal molecular weight (nmw) > 100 kD, A_II with nmw between 10 kD and 100 kD and R with nmw < 10 kD. Protease activity was determined in the fractions by using three different substrates: N-benzoyl-l-argininamide (BAA), specific for trypsin; N-benzyloxy-carbonyl-l-phenylalanyl l-leucine (ZPL), specific for carboxypeptidases; and casein, essentially a non-specific substrate. The derivative fractions were also analysed for their amino acid N and humic (HA) and fulvic (FA) acid contents. The organic matter of extracts and derivative fractions obtained from the pasture soil was analysed by isoelectric focusing (IEF) and that of fractions analysed by pyrolysis gas chromatography (Py-GC). Activities of the extract were monitored for their thermal stability and those of the extract and derivative fractions for their optimal pH.Due to the mechanical disintegrating action of sodium pyrophosphate over the humic substances during the fractionation process the amount of total organic C and FA in the fractions was ranked as R > A_II > A_I. The lowest amino acid N/organic C was found in the R fraction, whereas A_II fraction was rich in humic acids, carbohydrates and amino acid N and A_I fraction showed the lowest carbohydrate content. At least 70% of the total BAA- and ZPL-hydrolysing activity was associated to particles with nmw higher than 10 kD and at least 30% of these activities were present in particles with nmw higher 100 kD. Casein-hydrolysing activity was quite evenly distributed among the three fractions (A_I, A_II and R). The extracted protease-organic complexes were resistant to thermal denaturation and some of them showed optimal activity at pH values higher than 10 as a result of the polyanionic characteristics of the humic material surrounding enzyme molecules and of the presence of alkaline protease. Comparison of data obtained in Py-GC analyses and in protease activity suggests that BAA-hydrolysing activity was associated to a highly condensed humic matter and ZPL-hydrolysing activity to less resistant humic substances, while at least some of the extracted casein-hydrolysing activity was present as glyco-proteins not associated to humus. BAA-hydrolysing activity was probably inhibited by fresh organic matter of carbohydrate origin whereas lignin derived organic matter probably inhibited ZPL- and casein-hydrolysing activity.     

前处理过程中采用活性炭过滤对蔬菜有机磷农残测定的影响

[目的]了解活性炭对蔬菜有机磷农药残留测定的影响。[方法]在西葫芦样品中添加一定量的7种有机磷农药混合标准溶液制成一定浓度的模拟加标样品,进行活性炭过滤和不使用活性炭过滤2种前处理,气相色谱法测定蔬菜中有机磷农药残留。[结果]活性炭过滤处理的7种有机磷农药的回收率都低于不使用活性炭处理。活性炭过滤后,甲胺磷、乙酰甲胺磷、甲拌磷和毒死蜱的回收率都低于70%。不使用活性炭过滤处理的相对标准偏差为3.9%~7.7%,活性炭过滤处理的相对标准偏差为5.3%~18.2%,均符合要求。[结论]在前处理过程中采用活性炭过滤,会降低有机磷的回收率,影响测定结果,所以尽量不用活性炭。