气质联用同时测定食品中四种防腐剂

目的:研究建立气质联用同时测定各类食品中丙酸、山梨酸、脱氢乙酸、苯甲酸的方法。方法:在酸性条件下用乙醚提取目标物,采用改性聚乙二醇极性毛细管柱分离,通过选择合适的监测离子,建立气质联用方法,分别从回收率、精密度和检出限3个方面考察方法的适用性。结果:在0~2.0g/kg测定范围内,加标样品回收率为91.6%~101.2%,精密度为0.9%~2.1%,检出限为0.03~0.11 mg/kg。结论:该方法可以同时测定四种防腐剂,检出限优于常规方法,灵敏度高,并且缩短了检验周期,结果准确可靠,为今后大范围推广提供了理论依据。     

紫外分光光度法快速测定油炸食品中丙烯酰胺的含量

探讨了用紫外分光光度法测定不同食品样品中丙烯酰胺含量的新方法。与现在已有的方法(LC,GC,LC-MS,GC-MS,LC-MS-MS)相比,紫外法测定丙烯酰胺含量操作简便,对仪器要求小,适合丙烯酰胺的快速测定,便于食品企业、科研机构等的推广应用。试验结果表明:丙烯酰胺的吸光度与其浓度在0.25～6.0μg/L的范围内呈良好的线性关系,回归方程为:y=0.0958x+0.0294,(R=0.9875),回收率为90.07%～104.8%,RSD为0.5%。利用该方法测定了多种高温加工的食品中丙烯酰胺的含量,结果表明这些食品中丙烯酰胺的检出率为100%,但不同食品中丙烯酰胺的含量水平差异较大,这与其工艺技术不同有关。     

干灰化法-紫外可见分光光度法测定食品中铝的残留量分析

干灰化法在食品检测中显示出的优势相对明显,值得深入应用探究.基于此,本文主要从测定试验准备、样品预处理、测定试验方法流程三方面入手,对食品中铝的残留量测定中的干灰化法-紫外可见分光光度法主要内容进行分析,并提出检测参数优化方案,旨在为食品检测、食品安全保障提供更好支持.     

分光光度法在食品防腐剂检测中的应用

对紫外分光光度法、红外分光光度法、荧光分光光度法及原子吸收分光光度法在食品防腐剂检测中的应用进行了阐述。     

高效液相色谱法同时测定食品中12种防腐剂和甜味剂

目的建立高效液相色谱法同时测定食品中12种防腐剂和甜味剂的含量。方法样品经甲醇-水(30:70,V:V)提取,经Agilent TC C_(18)色谱柱分离,以甲醇/20 mmol/L乙酸铵水溶液为流动相进行梯度洗脱,流速为1.0mL/min,采用二极管矩阵检测器进行检测,检测波长为230 nm。结果 12种防腐剂和甜味剂在0.2~20μg/mL的浓度范围内呈现良好的线性关系,r~2≥0.9992,回收率在70.9%~115.6%之间,方法的检出限为0.001~0.005 g/kg。结论该方法具有高通量、操作简便等优点,可适用于食品中12种防腐剂和甜味剂的检测。     

食品添加剂苯甲酸的紫外分光光度法测定研究

本文建立了苯甲酸的紫外分光光度法，该方法简便准确。样品检验结果：最小检出量为０．００１２ｍｇ／ｍｌ，回收率达９７％，可以满足食品工业的生产和科研需要。     

分光光度法用于食品中锰含量的测定

建立用分光光度法测定食品大蒜、菠萝、茶叶中锰含量的方法,锰的含量在0.5～5 μg/mL范围内,吸收度与浓度成线性关系.线形方程为A=0.01427+0.07859c,相关系数r=0.9999.在实际样品中的回收率为90.9%～102.5%.该方法简单,准确,选择性好,不需对样品进行分离,适用于食品中微量锰含量的测定.     

HPLC法同时测定复合食品防腐剂中苯甲酸、山梨酸和脱氢乙酸

应用高效液相色谱法测定复合食品防腐剂中苯甲酸、山梨酸和脱氢乙酸的含量。样品用水提取后,甲醇和0.02mol/L乙酸铵15∶85(v/v)为流动相洗脱,经Syncronis aQ(4.6mm×150mm,5μm)色谱柱分离,二极管阵列检测器检测,检测波长为225nm。苯甲酸、山梨酸和脱氢乙酸的质量浓度在2 50mg/L的范围内与其峰面积成线性关系,线性方程分别为y=38273x-8760.9、y=48559x+10538、y=52126x+4283.4,检出限均为0.1mg/L。苯甲酸平均回收率为98.8%101.0%,相对标准偏差≤1.8%(n=6);山梨酸平均回收率为97.5%100.1%,相对标准偏差≤2.2%(n=6);脱氢乙酸平均回收率为99.5%101.0%,相对标准偏差≤2.2%(n=6)。该方法精确度和准确性好、灵敏度高,样品预处理简单,避免了滴定分析方法中复配防腐剂之间相互干扰的问题,是复合食品防腐剂中各种成分含量测定的理想检测方法。     

高效液相色谱法同时测定食品中7种防腐剂

目的建立一种采用高效液相色谱同时检测食品中苯甲酸、山梨酸、脱氢乙酸、对羟基苯甲酸甲酯、对羟基苯甲酸乙酯、对羟基苯甲酸丙酯、对羟基苯甲酸丁酯等7种防腐剂的方法,并对葡萄酒、饮料、酱油、面包等4种基质进行测定。方法样品经甲醇提取,无水硫酸镁除水离心后取上清液经0.45μm滤膜过滤,使用高效液相色谱二极管阵列检测器(DAD)对7种防腐剂含量进行测定。结果在优选条件下,方法线性范围为0.1~10 mg/L,线性相关系数R2≥0.9999,检出限(S/N=3)为50~100μg/L,样品回收率为77.28%~106.81%,相对标准偏差(RSD)为0.46%~2.38%。结论该方法操作简便,灵敏度高,适用于葡萄酒、饮料、酱油和面包4种基质中7种防腐剂的检测。     

超声萃取- 高效液相色谱法同时测定进出口食品中常见6 种防腐剂

使用超声萃取- 反相高效液相色谱(HPLC)技术,建立同时分离和检测食物中苯甲酸、山梨酸、对羟基苯甲酸甲酯、对羟基苯甲酸乙酯、对羟基苯甲酸丙酯和对羟基苯甲酸丁酯6 种防腐剂的方法。水- 甲醇(5:95,V/V)作为提取溶剂进行超声萃取,采用Supelco Discovery C18 反相色谱柱,流动相为乙腈- 乙酸铵缓冲溶液(pH4.4)进行梯度洗脱,在1ml/min 的流速和254nm 的检测波长下14min 内6 种防腐剂得到良好分离。6 种防腐剂线性范围从5μg/ml 到100μg/ml,相关系数(r)为0.9997～1.0000。方法的平均回收率为90.1%～106.3%,精密度和稳定性的RSD分别为0.58%～1.79%、0.15%～1.65%,检出限的范围为0.012～0.43μg/ml。本方法的预处理过程简便、快速,应用于30 种进出口食品中防腐剂的分析检测,检测结果灵敏、可靠。     

Simultaneous determination of nine kinds of preservatives in foods by HPLC

A simple and rapid HPLC method was developed for the simultaneous determination of nine kinds of preservatives, benzoic acid (BA), sorbic acid (SOA), dehydroacetic acid (DHA), methyl p-hydroxybenzoate (PHBA-Me), ethyl p-hydroxybenzoate (PHBA-Et), isopropyl p-hydroxybenzoate (PHBA-isoPu), propyl p-hydroxybenzoate (PHBA-Pu), isobutyl p-hydroxybenzoate (PHBA-isoBu) and butyl p-hydroxybenzoate (PHBA-Bu), in foods. For solid foods, the preservatives were extracted with methanol. After addition of 5 mmol/L citrate buffer to the extract, the extract solution was cleaned up on an Oasis HLB cartridge. The cartridge was washed with 5 mmol/L citrate buffer and methanol-5 mmol/L citrate buffer (4:6). Then, nine kinds of preservatives were eluted with methanol. The eluent was used for BA, SOA and DHA determination by HPLC. Furthermore, a part of the eluent was cleaned up on a Bond Elut PSA cartridge for p-hydroxybenzoate esters determination by HPLC. Liquid foods were cleaned up after addition of 5 mmol/L citrate buffer without the extraction process, and the subsequent procedure was the same as for solid foods. The recoveries of p-hydroxybenzoate esters from ten kinds of foods fortified at levels of 0.01 and 0.10 g/kg each were 91.5 to 107.4%, and those of BA, SOA and DHA were 76.4 to 104.8%. The quantitation limits of the preservatives in foods were 0.005 g/kg. (Received March 20, 2006)     

Simultaneous determination of aspartame and acesulfame-K by molecular absorption spectrophotometry using multivariate calibration and validation by high performance liquid chromatography

A new method to determine mixtures of two sweeteners, aspartame and acesulfame-K, in commercial sweeteners is proposed. A classical 5² full factorial design for standards was used for calibration in the concentration matrix. Salicylic acid was used as internal standard in order to evaluate the adjustment of the real samples in the PLS-2 model. This model was obtained from UV spectral data, validated by internal cross-validation and was used to find the concentration of analytes in the commercial samples. The PLS-2 method was validated externally by high performance liquid chromatography (HPLC), finding, in all cases, a relative error of less than 10% between the PLS-2 and the HPLC methods. The mean value of recovery degree in real samples was 99.2% with standard deviation of 3.2%. The proposed procedure was applied successfully to the determination of mixtures of aspartame and acesulfame-K in artificial sweeteners.     

分光光度法测定食品中的铝含量

依据国家标准方法[1]对样品的前处理和样品的测定进行研究.样品前处理采用干灰化法.在pH 6.0的乙酸-乙酸钠缓冲介质中,铝在聚乙二醇辛基苯醚(OP)和溴化十六烷基三甲胺的存在下与铬天青S形成稳定的四元混合胶束体系,其吸光度与铝含量在一定浓度范围内成正比.结果:摩尔吸光系数为7.1×10 4 L/mol·cm.铝含量在0.00～5.00 μg/25 mL呈良好的线性关系,相关系数r=0.9995,回收率在95.8%～99.8%之间.该法操作简单,显色灵敏、稳定、精密度和准确度高,适用于各种食品中铝含量测定的要求.     

Simultaneous determination of nine preservatives in food by liquid chromatography with the aid of coagulant in the clean-up process

ABSTRACT

A simple HPLC method was developed for the simultaneous analysis of nine preservatives in food including benzoic acid, sorbic acid, dehydroacetic acid, methyl paraben, ethyl paraben, isopropyl paraben, propyl paraben, isobutyl paraben and butyl paraben. Samples were extracted with 60 v/v% methanol containing poly-aluminium chloride (PAC) and sodium hydroxide prior to analysis. PAC, which is normally used as a coagulant, was successfully applied to remove interfering substances from the samples. The method showed good linearity with coefficients of determination higher than 0.999 over the range of 0.2–5 µg ml^–1 for all target preservatives. LOQs of the method were in the range of 0.002–0.008 g kg^–1. Method performance was evaluated in a variety of foods demonstrated to have quantitative recoveries of 81.7–102.5% with satisfactory intra-day precision of < 3.7% and inter-day precision of < 6.5%. The method also demonstrated applicability to real foods containing preservatives.     

Simultaneous determination of 21 preservatives in cosmetics by ultra performance liquid chromatography

An ultra performance liquid chromatography (UPLC) method has been developed for the simultaneous determination of 21 preservatives: 2-methyl-4-isothiazoline-3-ketone, bronopol, 5-chloro-2-methyl-4-isothiazoline-3-ketone, benzyl alcohol, 2-phenoxyethanol, methyl-p-hydroxy benzoate, ethyl-p-hydroxy benzoate, methyl benzoate, 4-hydroxybenzoic acid iso-propyl ester, propyl-p-hydroxy benzoate, 4-chloro-3-methylphenol, ethyl benzoate, 2-phenylphenol, 4-hydroxybenzoic acid iso-butyl ester, butyl-p-hydroxy benzoate, 4-chloro-3,5-dimethylphenol, phenyl benzoate, 2,4-dichloro-3,5-dimethylphenol, 2-benzyl-4-chlorophenol, triclocarban and triclosan in cosmetics. A Waters ACQUITY UPLC BEH C(18) column was used with 0.1% formic acid solution as the mobile phase under the condition of gradient elution. Preservatives were extracted with methanol by ultrasonicator, and then they were analysed by UPLC-PDA detector. All these preservatives were baseline separated in 8.5 min. The pre-treatment method of samples and the chromatographic condition of analysis were critically examined in this study. The recoveries ranged from 90.5 to 97.8%, with RSD values below 3.2%, and all correlation coefficients (r) were no less than 0.9997. Thus, this method could be used for analysing the preservatives in cosmetic products.     

多波长分光光度法测定牛乳中钙和镁

研究了在pH12时,铬天青S(CAS)-溴化十六烷基三甲铵(CTMAB)-钙和镁显色体系。采用盐酸煮沸分解,净化,借助于K-矩阵法同时测定了牛乳中钙和镁。结果表明,该方法对牛乳中钙和镁的添加回收率分别为102.0%～103.3%和103.3%～110.0%。     

反相高效液相色谱法同时测定果蔬中6种防腐杀菌剂

建立果蔬中6种防腐杀菌剂(噻苯咪唑、邻苯基苯酚、多菌灵、联苯胺、抑霉唑、联苯)同时测定的反相高效液相色谱法.样品用v(水):v(乙醇)=50:50超声萃取,过固相萃取小柱分离,浓缩定容,经ZORBAX Extend XDB-C18柱分离,以甲醇-水(pH8.0)为流动相,采用紫外检测器检测.6种防腐杀菌剂分离良好并排除了样品中杂质峰的干扰,加标平均回收率为95.7%～103.5%之间,相对标准偏差为0.24%～1.5%.检出限0.002～0.1 mg/L.该方法可同时简便、准确地测定果蔬中的6种防腐杀菌剂.     

气相色谱-质谱联用法同时检测调味品中7种防腐剂

利用气相色谱一质谱联用仪,优化了色谱、质谱仪器参数,利用质谱全扫描技术建立了同时检测酱油、醋、酱等4种调味品中山梨酸、苯甲酸、脱氢乙酸、对羟基苯甲酸甲酯、对羟基苯甲酸乙酯、对羟基苯甲酸丙酯、对羟基苯甲酸丁酯等7种防腐剂的方法.建立的方法以7种防腐剂的特征离子峰进行定性定量.7种添加剂的检测限分别为0.11,0.072,0.046,0.035,0.035,0.035,0.035 mg/kg,方法的精密度为2.9%～4.1%、回收率为85%～99%,应用于调味品中防腐剂的检测中效果良好,检测效率大大提高.