Determination of phthalate esters in Chinese spirits using isotope dilution gas chromatography with tandem mass spectrometry

Phthalate esters are additives used in polyvinylchloride and are found as contaminants in many food products. An isotope dilution mass spectrometry technique has been developed for accurate analysis of 16 phthalate esters in Chinese spirits by adopting the 16 corresponding isotope‐labeled phthalate esters. The ethanol in the spirit sample was first removed by heating with a water bath at 100°C with a stream of nitrogen, after which the residue was extracted with n‐hexane twice. The phthalates collected were identified and quantified by gas chromatography with tandem mass spectrometry in multiple reaction monitoring mode. The spiking recoveries of 16 analytes ranged from 94.3 to 105.3% with relative standard deviation values of <6.5%. The detection limits for 16 analytes were <10.0 ng/g. The expanded relative uncertainties were from 3.0 to 14%. A survey was performed on Chinese spirits from the market. Six of the nine analyzed samples were contaminated by phthalates. Di‐n‐butyl phthalate and di‐2‐ethylhexyl phthalate showed higher detection frequency and concentrations. This isotope dilution gas chromatography with tandem mass spectrometry method is simple, rapid, accurate, and highly sensitive, which qualifies as a candidate reference method for the determination of phthalates in spirits.     

Evaluation of Monolithic Columns for Determination of Formaldehyde and Acetaldehyde in Sugar Cane Spirits by High-Performance Liquid Chromatography

Abstract

High-Performance Liquid Chromatography (HPLC) conditions are described for separation of 2,4-dinitrophenylhydrazone (2,4-DNPH) derivatives of carbonyl compounds in a 10 cm long C₁₈ reversed phase monolithic column. Using a linear gradient from 40 to 77% acetonitrile (acetonitrile-water system), the separation was achieved in about 10 min—a time significantly shorter than that obtained with a packed particles column. The method was applied for determination of formaldehyde and acetaldehyde in Brazilian sugar cane spirits. The linear dynamic range was between 30 and 600 µg L^?1, and the detection limits were 8 and 4 µg L^?1 for formaldehyde and acetaldehyde, respectively.     

SPECTROSCOPIC STUDY ABOUT THE KINETICS OF THE ANTHOCYANIN PIGMENTS EXTRACTION DURING THE MACERATION OF CHERRIES IN LIQUOR

ABSTRACT

An experimental study of the effect of temperature on the kinetics of anthocyanin pigments extraction during the maceration of cherries (Prunnus avium) into a hard spirit is reported. The analytical method used was UV-Vis spectrophotometry. The initial extraction rate showed an Arrhenius-type dependency, with an apparent energy activation of 18.7±1.2 kcal/mol. Furthermore, a study about the evolution of the color (from colorless to red-orange) during the soaking process was made by calculating the CIE tristimulus values (X, Y, Z) for illuminant C, until to reach the apparent stabilization of color, what occurs after about two weeks for temperatures of 5°C and 23°C, whereas it happens after about four weeks for the other studied temperature (30°C).     

物理课堂的创新教育

营造宽松氛围,培养创新意识;创做多样情景．培养创新精神;灵活结合教材,培养创新能力。     

山西票号的经营精神及其传承

山西票号是我国最早产生的专门从事异地汇兑的民间金融组织,从票号经营者的气质看,始终渗透着中国传统文化和地域文化中的艰苦创业、崇尚信誉、以人为本的精神。这是票号能够在近代复杂的金融环境中生存百年的重要原因。如今,新晋商如果能秉承山西票号的经营精神并使之传承下去,将成为山西崛起的重要因素。     

试论奥林匹克运动的人文价值

“人奥运”是北京2008年奥运会的申办口号。在本中,作从人的视角阐述现代奥林匹克运动长盛不衰的化内涵,梳理澄清中国人精神对奥林匹克运动的积极作用。     

为市井细民写心--论宋元小说话本的写实精神

宋元小说话本是中国古代白话小说的开山之作,以市民阶层为主人公,描绘了他们的日常生活和思想意识;风格清淡朴实;在市民阶层的生活细节和思想意识方面都达到了高度的真实,具有写实精神.宋元小说话本的写实精神促进了中国世情小说叙事艺术的提高.     

物理学研究的美学精神

美是自然的属性，审美是人类的天性；物理学家在物理学研究中，用简单，对称，和谐美的原则对大自然规律进行审美描述，从而获得了许多重要的成果，物理学家坚信；美与真相伴，“由美求真”是认识自然规律的方法论原则之一；由这一原则出发，形成了物理学研究的美学精神，本文对此作了一些介绍。     

Study on different pre-treatment procedures for metal determination in Orujo spirit samples by ICP-AES

In this work several pre-treatment methods were studied for metal (Na, K, Mg, Cu and Ca) determination in Orujo spirit samples using inductively coupled plasma atomic emission spectrometry (ICP-AES). Dilution, digestion, evaporation, and cryogenic desolvatation techniques were comparatively evaluated. Because of their analytical characteristics, digestion and evaporation with nitrogen current were found to be appropriate procedures for the determination of metals in alcoholic spirit samples. Yet, if simplicity and application time are to be considered, the latter—evaporation in a water bath with a nitrogen current—stands out as the optimum procedure for any further determinations in Orujo samples by ICP-AES. Low detection levels and wide linear ranges (sufficient to determine these metals in the samples studied) were achieved for each metal. The recoveries (in the 97.5-100.5% range) and the precision (R.S.D. lower than 5.6%) obtained were also satisfactory. The selected procedure was applied to determine the content of metals in 80 representative Galician Orujo spirit samples with and without a Certified Brand of Origin (CBO) which had been produced using different distillation systems. The metal concentrations ranged between 0.37 and 79.7 mg L⁻¹ for Na, <LOD to 12.4 mg L⁻¹ for K, 0.02-4.83 mg L⁻¹ for Mg content, <LOD to 37.3 mg L⁻¹ for Cu and 0.03-13.10 mg L⁻¹ for Ca.     

Determination of volatile fatty acid ethyl esters in raw spirits using solid phase microextraction and gas chromatography

An analytical method for the determination of fatty acid ethyl esters in raw spirits of different quality or produced from various raw materials has been developed and optimized. A combination of headspace solid phase microextraction (HS-SPME) as the extraction technique and gas chromatography with flame ionization detection (GC-FID) as the determination technique was utilized. HS-SPME conditions such as: type of the stationary phase of the fiber, ethanol content, sample volume, extraction temperature and time, salt addition and sample agitation were investigated to determine the most suitable conditions for the analysis of volatile fatty acid ethyl esters in raw spirits. The quantification method was an internal standardization using methyl octanoate as the internal standard. The method's detection limits (MDLs) for the individual ethyl esters ranged from 26.8 to 0.0470 μg L⁻¹ 20% EtOH. The feasibility of SPME for the quantitative analysis of fatty acid ethyl esters in raw spirits of different organoleptic quality was demonstrated. High precision and simple sample preparation enable the use of this method for routine investigations in both industrial and research laboratories.