高效液相色谱法测定过氧化苯甲酰

过氧化苯甲酰已被广泛用作面粉及面粉制品的品质改良剂。它能提高其白度和贮藏性能,但若使用量过大,可使面粉制品在蒸煮过程中产生对人体有害的物质。我国GB/T2760-1996中规定其使用量为0.06g·kg-1,但无国家标准的检验方法,本文采酰在0.0～2.00mg范围内呈线性关系,相关系数为0.9998,相对标准偏差为4.66%,回收率为89.5%～118.0%。1　试验部分1.1　原理样品中过氧化苯甲酰以丙酮和乙醇溶解,在酸性介质中被碘化钾还原为苯甲酸后,测定苯甲酸即可求出过氧化苯甲酰的含量。1.2　仪器与试剂高效液相色谱仪(美国PE公司,附紫外检测器)PE4.6mm…     

过氧化苯甲酰的安全性研究

利用分子结构特性对过氧化苯甲酰的分解原理进行了分析,并通过热分析、撞击感度和爆发点试验对其安全性进行了评价,得到相关的安全数据。     

过氧化苯甲酰检测方法研究

针对当前面粉中添加剂严重超标的现象,本文分析了面粉中过氧化苯甲酰超标的原因,对影响过氧化苯甲酰检测的因素进行研究,并提出改进过氧化苯甲酰含量测定的方法。新方法简便易行,准确度高,可为企业生产、使用过氧化苯甲酰提供依据。     

高效液相色谱法测定面粉中过氧化苯甲酰

由于过氧化苯甲酰具有使面粉增白、增筋及杀菌等效果 ,故面粉加工工艺中用其作为面粉改良剂。但有些面粉加工厂 ,为改善面粉的感官性状 ,以次充好 ,随意过量添加过氧化苯甲酰。而现在国内尚无测定面粉及其制品中过氧化苯甲酰的标准方法。本文对照文献 [1],试验了面粉中过氧化苯甲酰的高效液相色谱法。样品中过氧化苯甲酰用无水乙醇提取 ,用碘化钾将其还原为苯甲酸 ,ＯＤＳ Ｃ18柱分离 ,紫外检测器 2 30ｎｍ检测 ,以保留时间定性 ,峰面积定量。本法检出限为 1.0ｍｇ·Ｌ- 1,回收率大于86 5 % ,平均相对标准偏差 5 .2 % ,本法操作简便 ,能满…     

光度法测定小麦面粉中过氧化苯甲酰

在磷酸介质中,过氧化苯甲酰氧化碘化钾生成的碘与淀粉显色,在585nm波长处有最大吸收峰,建立了碘化钾碘蓝光度法间接测定微量过氧化苯甲酰的方法。过氧化苯甲酰的质量浓度在0．016g·L^-1以内呈线性。方法应用于新出产的小麦面粉中过氧化苯甲酰的测定,回收率在93．3％以上。     

HPLC法测定沙河粉中的过氧化苯甲酰

采用高效液相色谱法测定沙河粉中的过氧化苯甲酰 ;选用DiamonsilC18(5μm,200×4.6mm)色谱柱 ,流动相 :0.02mol/LNH4Ac-甲醇(体积比95∶5) ;检测波长 :220nm ;流速 :1.0mL/min ;柱温 :室温 ;进样量 :10μL ;方法的线性关系良好 ,相关系数r=0.9994 ,样品的最低检出浓度为0.003g/kg,回收率为92 %～102 % ,RSD=1.1 % ;本方法对检测过氧化苯甲酰具有应用价值。     

Decomposition of Benzoyl Peroxide in the Presence of Ferrocene

Russian Journal of General Chemistry - Decomposition of benzoyl peroxide in the presence of ferrocene has been shown to proceed simultaneously via several pathways—thermal decomposition, the...     

过氧化苯甲酰的测定与应用研究

本文提出了一种以丙酮为溶剂,柠檬酸为催化剂和掩蔽剂的间接磺量法以测定过氧化苯甲酰。该方法简便易行,重现性好,准确度高,测定结果令人满意。     

面粉增白剂过氧化苯甲酰

阐述了过氧化苯甲酰的理化性质及作为面粉增白剂对面粉的增白机理,并对过量添加的危害进行了探讨。     

Kinetic Features of Decomposition of Benzoyl Peroxide in Superbasic Media

Kinetics of decomposition of benzoyl peroxide in superbasic media comprising mixtures of a dipolar aprotic solvent and a strong ionic base is studied. The process occurs in two steps through formation of intermediate perbenzoate anion. The contribution of ionic reactions is controlled by the polarity and dielectric constant of the solvent. The decomposition products are molecular oxygen and an alkali metal benzoate or perbenzoate. These products can be alkylated with butyl bromide in superbasic media.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 5, 2005, pp. 803–808.Original Russian Text Copyright © 2005 by Lyavinets.     

高效液相色谱法测定乳清粉和黄油中过氧化苯甲酰

应用高效液相色谱法(HPLC)测定了乳清粉和黄油中过氧化苯甲酰的含量。对含脂肪较低的样品,可直接加入乙腈进行提取,经振摇和离心后取上清液,用0.45μm滤膜过滤,滤液用于HPLC分析。对含脂肪较高的样品,须先用正己烷脱脂,然后用经正己烷饱和的乙腈提取3次,合并提取液经0.45μm滤膜过滤后供HPLC分析。采用Agilent TC C_(18)色谱柱及由甲醇-水(65+35)混合液作为流动相进行分离,并在236nm波长处进行紫外检测。过氧化苯甲酰的质量浓度在0.1～1.0mg·L~(-1)范围内与其相应的峰面积呈线性关系。方法的测定下限(10S/N)为1.0 mg·kg~(-1)。以乳清粉及黄油样品为基体,用标准加入法在3个浓度水平(1,5,10mg·kg~(-1))上对方法进行回收试验,测得回收率在96.6%～104.0%之间,测定值的相对标准偏差(n=6)均小于7.0%。     

核-壳型过氧化苯甲酰印迹溶胶-凝胶聚合物的制备及应用

以过氧化苯甲酰为模板分子,采用溶胶-凝胶印迹技术在自制的二氧化硅微球表面成功制备对过氧化苯甲酰具有特异性吸附能力的核-壳型印迹材料,并由红外光谱、扫描电镜和差热分析表征了印迹聚合物。该印迹微聚合物分散性好、热稳定好、平均粒径为300nm,印迹聚合物的壳层厚度为50nm。用高效液相色谱研究了印迹聚合物的吸附性能,结果表明该印迹聚合物对过氧化苯甲酰的选择系数为6.59。作为固相萃取材料,该印迹材料已被成功用于面粉中过氧化苯甲酰的分离和富集,回收率为94.98%。     

毛细管柱气相色谱法测定小麦粉中过氧化苯甲酰

合成了对甲苯磺酸三正丁铵,并以二氯甲烷为溶剂,用静态法涂敷于石英毛细管色谱柱上(30 m×0.53 mm i.d.,液膜厚度为1.2 μm)作为气相色谱的固定相,对柱性能进行了考察.试验表明此色谱固定相极性较强,对于小麦粉中过氧化苯甲酰有独特的分离作用,在3个不同的浓度水平上作方法的精密度试验,得到的相对标准偏差值在1.1%～5.0%之间,线性范围为10～100 mg·L-1(r=0.994),检出限为2.0 mg·kg-1;方法的回收率为90.5% ～95.0%.     

Theoretical Studies on Thermal Decomposition of Benzoyl Peroxide in Ground State

Systematic studies of the thermal decomposition mechanism of benzoyl peroxide(BPO) in ground state,leading to various intermediates, products and the potential energy surface(PES) of possible dissociation reactions were made computationally. The structures of the transition states and the activation energies for all the paths causing the formation of the reaction products mentioned above were calculated by the AM1 semiempirical method. This method is shown to to be one predict correctly the preferred pathway for the title reaction. It has been found that in ground state, the thermal decomposition of benzoyl peroxide has two kinds of paths. The first pathway PhC(O)O--OC(O)Ph→PhC(O)O→Ph CO2 produces finally phenyl radicals and carbon dioxide. And the second pathway PhC (O) OO--C (O) Ph→PhC (O) OO PhC (O)→PhC(O) O2→Ph CO O2, via which the reaction takes place only in two steps, produces oxygen and PhC(O) radicals, and the further thermal dissociation of PhC(O) is quite difficult because of the high activation energy in ground state. The calculated activation energies and reaction enthalpies are in good agreement with the experimental values. The research results also show that also the thermal dissociation process of the two bonds or the three bonds for the benzoyl peroxide doesn‘t take place in ground state.     

Efficient and Alternative Approach for Preparation of O-Benzoyloximes Using Benzoyl Peroxide

Benzoyl peroxide has been used as a mild and efficient reagent for the preparation of benzoyl ester of oxime in moderate to good yields.     

Spectrophotometric Quantitation of Fluoxetine Hydrochloride Using Benzoyl Peroxide and Potassium Iodide

 Fluoxetine hydrochloride reacts with benzoyl peroxide and potassium iodide, after heating for 1 min at 30 °C, to give a blue colour having maximum absorbance at 570 nm. The reaction is selective for fluoxetine with 0.01 mg/mL as visual limit of quantitation and provides a basis for a new spectrophotometric determination. The colour reaction obeys Beer’s law from 0.1 mg/10 mL to 2.0 mg/10 mL of fluoxetine and the relative standard deviation is 0.68%. The qualitative assessment of tolerable amounts of other drugs is also studied. Received September 21, 1998. Revision September 10, 1999.     

Kinetics and Mechanism of Bilirubin Oxidation by Benzoyl Peroxide in Dimethyl Sulfoxide

The kinetics of the redox reaction of bilirubin by the action of benzoyl peroxide in dimethyl sulfoxide was analyzed. It is shown that the first reaction product is biliverdin, which oxidizes to purpurin and further to choletelin. The kinetic and activation parameters of the oxidation reactions were obtained. A kinetic model of the process was proposed. An assumed route of the reaction is related to the exchange interaction of CH protons of methylene and methine spacers with free radicals in the rate‐limiting step with the further destruction of the “ridge‐tile” pigment conformation. The mechanism steps are confirmed by quantum‐chemical calculations and HPLC. It is found that in organic solvents the end products of bilirubin oxidation are not monopyrrolic derivatives. The data obtained will be useful in constructing antioxidant action models of the pigment.     

高效液相法测定面粉中的过氧化苯甲酰

 报道了测定面粉中过氧化苯甲酰含量的一种改进方法。面粉直接以石油醚萃取 ,采用Shim PackVP ODS柱 (0 46cmi d × 1 5cm ,5μm～ 6μm) ,以乙腈 体积分数为 0 3 %的磷酸水溶液 (体积比为 4∶1 )为流动相 ,流速1 0mL/min ,检测波长 2 36nm。在此条件下 ,过氧化苯甲酰和苯甲酸的质量浓度分别和其峰面积呈良好的线性关系 ,过氧化苯甲酰的线性范围为 0 0 0 2 g/L～ 0 0 1 2 g/L(r =0 9995) ,最小检测量为 0 0 0 5g/kg;苯甲酸的线性范围为 0 0 0 2g/L～ 0 0 1 2g/L (r =0 9993) ,最小检测量为 0 0 1g/kg。