2nd and 3rd Order Derivative Spectrophotometric Determination of Ascorbic Acid in Soft Drinks

Abstract

A method is developed for the 2nd and 3rd order derivative spectrophotometric determination of 0.5–6 and 0.5–7 μ.ml^?1 of ascorbic acid, respectively. For its determination in soft drinks a blank solution is prepared from the soft drink to be analyzed in order to avoid the interference from the other additives and colouring matter present.     

多波长线性回归导数分光光度法同时测定饮料中糖精钠和苯甲酸

测定了同时测定两组分的多波多线性回归导数分光光度法,无需进行化学分离。方法用于模拟样品和饮料样品中糖精钠和苯甲酸的同时测定,回收率为９８％￣１０１％,相对标准偏差〈３．０％。     

比值导数波谱-多波长最小一乘回归分光光度法同时测定饮料中糖精钠、苯甲酸和山梨酸

提出了比值导数波谱－多波长最小一乘回归分光光度法。该法能同时测定三组分混合物而毋需零交点波长和等吸收点，且回归稳健性好．可消除异常点的影响。方法用于合成样品和饮料中糖精钠、苯甲酸和山梨酸的同时测定，相对误差＜± ３． ５％，回收率为 ９６． ６％～１０４．４％，相对标准偏差为２．０％～３．１％．     

Quantitative Determination of Miconazole in Creams by Second Order Derivative Spectrophotometry

ABSTRACT

A derivative spectrophotometry was developed to determine miconazole in cream formulations that contain benzoic acid as preservative. The procedure was based on the linear relationship in the range 100-500 μg ml^?1 between the drug concentration and the second derivative amplitudes at 276 nm. Results of the recovery experiments performed on various amounts of benzoic acid and of the determination of miconazole in cream confirmed the applicability of the proposed method to complex formulations.     

紫外分光光度法同时测定面粉中过氧化苯甲酰及其还原产物苯甲酸的含量

建立了一种测定面粉中过氧化苯甲酰及其还原产物苯甲酸含量的紫外分光光度法。采用无水乙醇作参比,在同一样品溶液中分别于233 nm和226 nm处同时测定过氧化苯甲酰及其还原产物苯甲酸的含量,由于两组分同时测定时相互影响,通过建立线性方程组的方法消除被测组分间的相互干扰,过氧化苯甲酰在8.26×10-6~4.95×10-6mol/L和苯甲酸在1.64×10-5~9.84×10-5mol/L范围内服从比耳定律。该法操作简便、快速,不经提取分离同时测定面粉中过氧化苯甲酰及其还原产物苯甲酸含量获得了较满意的结果。     

高效液相色谱法测定高脂类酱腌菜中苯甲酸、山梨酸的含量

建立了高效液相色谱法测定高脂类酱腌菜中苯甲酸、山梨酸含量的测定方法.样品用乙醚高速匀浆的方法提取后,通过改变其酸碱度而改变其在有机相和水相中分配比的方法,去除脂肪等杂质的干扰,采用C18分离柱,用甲醇∶乙酸胺溶液(5∶95,V/V)作为流动相,检测波长为230 nm,同时测定苯甲酸、山梨酸.2种组分的检出限分别为为0.3 mg/kg0、.25 mg/kg,回收率在94.1%~105.0%之间,测定结果的相对标准偏差为1.3%~2.1%.     

酯化衍生气相色谱新法测定苯甲酸与山梨酸

In this paper, it is described that tetramethyl ammonium saIts of sorbic,benzoic and phenylacetic acids reactwith 1-iedobutane directly in N,N-dimethylformamide solution to forrn butyl esters of the corresponding acids. The butyl esters can be well separated by gas chron1atography on a column packed with 5%SE-30/102 silanizedwhite support.This methed has been used for the determination of benzoic and sorbic acids in ffors and drinks。The analysis is simple,fast and accurate.     

多元校正流动注射电位滴定法同时测定苯甲酸和山梨酸

将流动注射应用于酸碱电位滴定分析,建立了一种可同时测定混合有机酸的电位滴定新方法。在该方法中,用氢氧化钠与氯化钾的混合溶液作为滴定剂,在流通池中同时插入pH指示电极和氯离子指示电极,在滴定过程中的任一滴定点,流出液的pH值和酸碱的混合比例可由两个电极的电位测定值同时获得,从而可应用多元校正法由相应的滴定曲线求得混合酸中每一种组分的含量。该方法不仅免去了体积和时间读数,而且减少了试剂和样品的消耗量,分析速度快。应用该方法对混合样品中的苯甲酸和水杨酸进行同时测定,其相对标准偏差分别为0．19％～0．37％,回收率分别为97．3％～102．6％。     

高效液相色谱-串联质谱法测定调味料中的痕量苯甲酸与山梨酸

建立了调味料中痕量苯甲酸、山梨酸的高效液相色谱-串联质谱检测方法.调味料样品经盐酸酸化后用乙醚多次提取,酸性氯化钠洗涤提取液,挥干后用1 mL90% 0.2 mmol/L NH4OAc(pH 5.0)的乙腈溶液溶解,过膜备用.采用电喷雾负离子电离(ESI-)模式和单反应监控(SRM)模式检测,外标法定量.该方法在0.5...     

Simultaneous Determination of Perphenazine and Amitriptyline by Derivative Spectrophotometry

Abstract

Two methods have been developed for the simultaneous determination of Amitryptiline and Perphenazine: the zero-crossing (I) and the derivative ratio spectrum (II) methods and both use the derivative spectrophotometry.

The methods have been applicable in the ranges of 1 to 30 μg·ml^?1 of Amitryptiline (I and II) and between 1 and 8 μg·ml^?1 and from 1 to 7 μg·ml^?1 of Perphenazine for the methods I and II respectively. The accuracy of the proposed methods have been studied and they have been used in the determination of Amitryptiline and Perphenazine in commercially available pharmaceuticals.     

比值导数光谱与多波长最小二乘回归分光光度法同时测定苯甲酸、苯甲醛和苯甲醇

提出了比值导数光谱多波长最小二乘回归分光光度法测定苯甲酸、苯甲醛和苯甲醇三组分混合物。合成试样４ 次平行测定的相对标准偏差为０ ．１６ ％ ～４．３５ ％ 。回收率在９１ ．４３ ％ ～１０５．９ ％ 之间。     

以四(对羟基苯基)卟啉作显色剂组合导数分光光度法同时测定锌、镉的研究

本文利用“组合导数分光光度法”,在碱性介质中,以四(对-羟基苯基)卟啉作显色剂,以咪唑作催化剂,对锌、镉的同时测定进行了详细研究。该法使测定锌的表观摩尔吸光系数提高到10~6L·mol~(-1)·cm~(-1),同时解决了重叠谱带相互干扰的问题。对合成样品进行分析,结果令人满意。     

高效液相色谱法同时测定葡萄酒中的乙酰磺胺酸钾、糖精钠、苯甲酸、山梨酸

首次建立了高效液相色谱法同时测定葡萄酒中乙酰磺胺酸钾(安赛蜜)、糖精钠、苯甲酸、山梨酸含量的方法.样品水浴去除乙醇,用流动相甲醇+乙酸铵(3:7,V/V)定容,采用PACKING FUJI SPS100 C18柱,(250×4.6mm,5μm)进行等度洗脱分离.乙酰磺胺酸钾、糖精钠、苯甲酸、山梨酸在1~100μg/mL范围内,线性关系良好,回归系数R2高于0.999 9,回收率88.4%~99.8%,精密度0.12%~1.84%,最低检出限均达到1.0μg/mL.方法准确、快速、灵敏度高,重现性好,满足食品中添加剂的检测要求,适用于葡萄酒中添加剂的分析检测,是葡萄酒质量监控强有力的技术支撑.     

Simultaneous Determination of Atrazine and Chlorpyrifos in Pesticide Formulations,in Soils and Waters by Derivative Spectrophotometry and Ratio Spectra Derivative

Abstract

A new method is described to analyse a binary mixture of atrazine and chlorpyrifos, using first-derivative spectrophotometry for atrazine and first derivative of the ratio spectra for chlorpyrifos. The procedure does not require any separation step. Calibration graphs were linear up to 15 μg.mL^?1 of atrazine and to 10 μg.mL^?1 of chlorpyrifos. The method has been applied to determine both compounds in pesticide formulations, in soils and waters.     

微波消解-零交截距导数分光光度法同时测定催化剂中钴和镍

采用微波法消解催化剂 ,研究确定了微波消解催化剂的最佳工作条件。应用零交截距导数分光光度法解决了 PAR- CO2 +、PAR- Ni2 +体系中 Co2 +、Ni2 +的同时测定。钴和镍的线性范围分别为 0～ 30 μg/ 2 5m L和 0～ 2 5μg/ 2 5m L,催化剂样品中钴和镍测定结果的相对标准偏差 (n=5)分别≤ 1 .5%和≤ 1 .0 % ,与标准值相对误差分别≤± 1 .5%和≤± 2 .1 %。本方法测定催化剂中钴和镍 ,酸用量少 ,降低了环境污染     

咪唑离子液体用于反相色谱流动相添加剂分析苯甲酸和山梨酸

开展了咪唑离子液体用于反相色谱流动相进行苯甲酸和山梨酸分析的研究。考察了咪唑离子液体种类与浓度、甲醇浓度、紫外检测波长等因素对分离、检测苯甲酸和山梨酸的影响,并探讨了2种分析物的保留规律。建立了以咪唑离子液体为流动相添加剂的反相色谱测定苯甲酸和山梨酸的分析方法。采用Agilent ZORBAX ODS反相色谱柱,以甲醇-0.2 mmol/L氯化1-丁基3-甲基咪唑水溶液(40∶60,体积比)为流动相,紫外检测波长230 nm,流速1.0 mL/min,色谱柱温度35℃时,可在7.0 min内实现苯甲酸和山梨酸的分离和检测。苯甲酸和山梨酸的线性范围为1.0～100.0 mg/L,相关系数(r)高于0.999 5,检出限均为0.02 mg/L。将方法应用于饮料样品中苯甲酸和山梨酸的测定,加标回收率为93.9%～104%,相对标准偏差(RSD)不大于4.0%,满足定量分析的要求。     

HPLC法同时测定饮料中维生素C、苯甲酸和山梨酸

近年来,维生素强化食品日益风行,市场上有许多饮料都标明富含维生素C,且不含防腐剂,因此建立一种同时快速、准确测定维生素C和防腐剂的方法具有重要意义。维生素C的常规分析方法有微生物法、荧光法和比色法,苯甲酸和山梨酸则可采用薄层色谱、气相色谱或高效液相色谱法进行测定。     

场强放大样品进样-毛细管电泳技术对中药制剂中苯甲酸与山梨酸的测定

利用场强放大样品进样-高效毛细管电泳分离技术测定中药口服制剂中苯甲酸和山梨酸的含量。采用未涂层熔融石英毛细管柱(50.2 cm×75μm,有效长度40 cm),以pH 9.5的50 mmol/L硼砂为运行缓冲液,柱温25℃,分离电压20 kV,PAD检测,检测波长228 nm。阳极进样,进样前压力进水3.45 kPa×5 s,电动进样-10 kV×3 s。在最佳富集条件下,苯甲酸和山梨酸的富集倍数(以峰面积计)可达259.7和231.9倍;在0.5~20.0 mg/L范围内呈良好的线性关系,相关系数高于0.995,检出限分别为0.67、0.53μg/L。将此方法用于两种液体中药制剂中苯甲酸和山梨酸的测定,苯甲酸的回收率为98%~103%,山梨酸的回收率为100%~101%。该法简单快速、准确可靠、灵敏度高、无需复杂仪器,为液体中药制剂中防腐剂的含量控制提供了新的检测方法。     

Simultaneous Determination of Lanthanum and Europium by Higher Order Derivative Molecular Absorption Spectrophotometry

Abstract

The identical properties of rare earth elements towards reaction with various chromogenic reagents in molecular absorption spectrophotometry (MAS) leads to a requirement for the development of procedures with greater selectivity. One way of solving this problem is by utilizing derivative spectroscopy, where the composite spectrum is transformed to the second or higher order derivative in wavelength domain. This paper reports the utilization of higher order derivative spectrophotometry for the simultaneous determination of lanthanum and europium. The developed procedure is simple, reliable and allows the determination of as low as 100 and 10 ppb of lanthanum and europium. respectively. Similar methodology can be adopted for the simultaneous determination of two or more of any closely related analytes by proper choice of derivative order in addition to selecting a suitable chromogenic reagent, pH and masking agents.