Report by the Analytical Methods Committee. Nitrogen factors for chicken meat

Recent studies have raised doubts about the relevance of the nitrogen factors for chicken meat recommended by the Analytical Methods Committee in 1963 when applied to the chicken meat currently being processed. The Nitrogen Factors Sub-Committee was asked to carry out a reappraisal of the chemical composition of chicken meat. It was informed that the majority of meat produced in the UK came from either of the breeds Ross or Cobb and one or other of the categories broilers (male or female, killed at 5 weeks), heavy broilers (male, killed at 7/8 weeks) and hens. Selected birds from these categories were dissected into samples representing breast, leg, thigh, other meats and skin and these were analysed for fat, moisture, nitrogen, ash and hydroxyproline content. The separate results for breast, leg, thigh, skin and other meats were combined mathematically to give figures for whole birds. From these results it was possible to recommend nitrogen factors for the individual joints and for the entire carcases, with and without skin, for broilers and hens. These factors are lower than those recommended in 1963.     

Methods for the determination of sulphonamides in meat.

Sulphonamides, due to their important antibacterial effects, are widely used in veterinary practice and animal husbandry. Residues arising from administration without observing withdrawal time sufficiently are normally the parent compounds and the N4-acetyl derivatives, the latter being hydrolyzed to the parent compounds only during extraction under acidic conditions. It is therefore quite conceivable that many authors concentrate on determining these metabolites. In the past decade, we have witnessed a considerable increase in new analytical techniques dealing with the determination of sulphonamides. Among these procedures, especially the so-called multimethods using high-performance liquid chromatography--though sometimes including toilsome clean-up steps--can be mentioned. However, current approaches also utilize gas chromatography, gas chromatography-mass spectrometry, liquid chromatography-mass spectrometry, supercritical fluid chromatography-mass spectrometry, thin-layer chromatography and immunological methods. For most of these techniques, a strong trend towards lowering the level of detectability (down to the sub-ppb range) and improving accuracy and reproducibility can be established.     

有机硫代磷酸酯的液相色谱分离分析方法的研究

研究了有机硫代磷酸酯的大孔阴离子交换柱色谱族组分分离、ＨＰＬＣ单体组分分析以及半制备ＨＰＩ工单体组分分离方法,同时给出了各种硫代磷酸酯的ＵＶ光谱、ＩＲ光谱、ＮＭＲ和ＦＤＭＳ特征。     

锂元素的分析方法探讨

总结了国内外关于测定锂元素的分析方法,内容主要包括质量分析法、光谱分析法和波谱分析法,并侧重分析了各种方法的优缺点,指出了提高锂分析结果精度的可能途径。     

Analytical Methods for the Characterization of Vegetable Oils

The determination of the authenticity of extra virgin olive oils (EVOOs) has become more interesting in recent years. Italy is the first country in Europe in terms of number of Protected Designation of Origin (PDO) oils, which connects consumers to a feeling of tradition and thus to higher quality standards. This work focused on the consideration of the inorganic content as a possible marker of EVOOs. Ten vegetable oils (VOs), eight Italian EVOOs and seven not Italian EVOOs were analyzed. After pretreatment by acid mineralization, Al, Ba, Ca, Cu, Fe, K, Li, Mg, Mn, Na, P, Sb, Se and Zn were determined by ICP-OES. The electrochemical properties of a selected group of EVOOs and other vegetal oils of different botanical origin were investigated by voltammetry. Carbon paste electrodes (CPEs) were prepared. The features observed in the voltammograms reflect the reactions of electroactive compounds, which are present in the oils. A chemometric treatment of the results was performed to assess the possibility to distinguish (i) the region of provenience considering the inorganic profile; and (ii) the plant species from which each oil was obtained on the basis of the current profile registered during voltammetric analysis. Inorganic composition seems to be a useful marker for the assessment of the geographical origin of an EVOO. The EVOO-CPEs voltammetry seems to have a good ability to distinguish the plant species of origin. This method could be useful to monitor the conservation status of the oils, as the redox profile is linked to the oxidative degradation state.     

秋水仙碱分析方法的研究概述

针对秋水仙碱作为治疗急性痛风性关节炎药物的应用,综述了国内外秋水仙碱测量方法研究进展,重点介绍了伏安法、高效液相色谱法、高效液相色谱-质谱联用法等的研究情况.     

Pattern Recognition as a Procedure for Selecting Analytical Methods for Solving Analytical Problems. A Preliminary Investigation

Abstract

A first step towards developing a calculation method, predicting the analytical method suitable to solve a distinct analytical problem, is described.

With pattern recognition, a binary decision maker is calculated, deciding the analytical method from two alternatives, w-vie spectrometry and atomic absorption spectrometry. This procedure yielded a 85% predicting accuracy.     

酚类环境雌激素的色谱分析方法

综述了近年来酚类环境雌激素的色谱分析研究进展,包括气相色谱和气质联用,高效液相色谱和各种检测器联用技术。比较了使用气相色谱和液相色谱两种方法的优缺点,并对环境雌激素样品预处理作了介绍。     

Analytical Methods for Speciation of Organotins in the Environment

The growing awareness over the environmental fate of organotin compounds is reflected in the large number of analytical methods developed for their separation. Organotin compounds have varying degrees of toxicological properties, depending on the nature and number of alkyl groups bonded to the tin atom. Most of the analytical speciation methods applied to actual environmental media have involved prior derivatization to transform organotin compounds into volatile hydrophobic analytes amenable to separation and identification by gas chromatography coupled to a sensitive and selective tin-detector. Evidence exists that members of the same homologous series are related by environmental degradation pathways. Chemical treatment prior to analysis, or high temperatures associated with gas chromatography separation, may alter the relative amounts of organotins in samples and blur the true environment picture. To avoid species redistribution that may occur during derivatization or gas speciation analysis, methods based on liquid chromatography and supercritical fluid chromatography have been investigated. This review documents analytical methods for determination of tin and speciation of organotin compounds, in the hope that it will be of value to those interested in initiating a programme for assessing the impact of such species on the environment.     

Determination of the Nitrogen Content of Cationic Cellulose Fibers by Analytical Pyrolysis

Summary.  Analytical pyrolysis in combination with gas chromatography and mass spectrometry or a nitrogen-phosphorus detector, respectively, were used to characterize the quaternization reagent glycidyltrimethylammonium chloride and a cationic cotton fabric. Trimethylamine was shown to be the most abundant nitrogen-containing product in the pyrolysis of glycidyltrimethylammonium chloride and was thus used for the quantification of the nitrogen content of the cationic cotton fabric. The results were compared to those obtained by traditional methods such as Kjeldahl and elemental analysis. It could be shown that pyrolysis is well suited for monitoring the nitrogen content of cellulose fibers. Received July 11, 2001. Accepted (revised) August 2, 2001     

草甘膦分析方法的研究进展

介绍了1990—2010年间草甘膦的定性、定量分析方法,包括红外光谱法、核磁共振法、分光光度法、色谱法、化学发光法等(引用文献50篇)。     

蝶呤类化合物分析方法研究进展

本文概述了国内外蝶呤类化合物分析方法的研究现状,包括高效液相色谱法、荧光分析法、免疫分析法、毛细管电泳法等,同时对人体的尿液和血液等样品的前处理方法进行了介绍。引用文献49篇。     

Determination of the Nitrogen Content of Cationic Cellulose Fibers by Analytical Pyrolysis

 Analytical pyrolysis in combination with gas chromatography and mass spectrometry or a nitrogen-phosphorus detector, respectively, were used to characterize the quaternization reagent glycidyltrimethylammonium chloride and a cationic cotton fabric. Trimethylamine was shown to be the most abundant nitrogen-containing product in the pyrolysis of glycidyltrimethylammonium chloride and was thus used for the quantification of the nitrogen content of the cationic cotton fabric. The results were compared to those obtained by traditional methods such as Kjeldahl and elemental analysis. It could be shown that pyrolysis is well suited for monitoring the nitrogen content of cellulose fibers.     

辣椒素的分析方法比较

采用可见、紫外分光光度法和高效液相色谱法(HPLC)对辣椒不同部位的辣椒素含量进行了对照分析,同时用上述三种方法对色素、辣椒精及辣椒素晶体的辣椒素含量进行了对照分析。分析结果表明,HPLC方法与前两种方法相比,具有方法可靠、测得的结果准确度高等优点。     

Modern Analytical Methods for Monitoring Workplace Atmospheres

Abstract

Since measurements of exposure to hazardous substances were made obligatory in Germany under the Hazardous Material Regulation and Regulations for Accident Prevention there has been a need for widely-applicable, economic methods for determining airborne organic substance concentrations at workplaces. The relevant limits, which are based on toxicological and industrial hygiene data, are drawn up annually by the German Science Foundation and published as “Technische Regel für gefährliche Arbeitsstoffe” (TRgA 900) by the Ministry of Employment and Welfare.

Most organic substances, that have been assigned limits can be determined by gas liquid chromatography. The system described here is based on multicomponent GLC analysis. It has been used at BASF, the chemical-manufacturing company, where since 1979 approximately fifteen thousand workplaces have been evaluated. Hazardous substances have been detected at levels down to a few micrograms per cubic meter.

The standard system encompasses:

–-personal air samplers operating for 8 h;

–-adsorption by a solid sorbent;

–-desorption by solvent;

–-simultaneous GLC-separation on two different capillary columns;

–-computer correlation of the qualitative and quantitative data of the two chromatograms (plausibility check);

–-automatic print-out of the analytical report;

–-transfer of the results to a data bank for documentation.

Details are given of the method involving adsorption on activated charcoal and desorption with carbon disulfide. Benefits, cost advantages, and limitations are discussed.

Special sampling by means of other adsorbents (e.g. silica gel) in conjunction with special desorption, formation of derivatives, headspace analysis, and adsorption by liquids are techniques used to supplement the standard method of organic trace analysis in the field of industrial hygiene.     

Development of a polymerase chain reaction and capillary gel electrophoresis method for the detection of chicken or turkey meat in heat-treated pork meat mixtures

A polymerase chain reaction and capillary gel electrophoresis (PCR-CGE) method with ultraviolet (UV) or laser induced fluorescence detection (LIF) was established for the detection of chicken or turkey in heat-treated pork meat mixtures. Mitochondrial DNA samples extracted from heat treated meat were amplified with their corresponding specific primers yielding PCR products between 200 and 300 bp. LIF detection was superior than UV detection in terms of precision and sensitivity for the study of DNA fragments. The CGE-LIF method was highly reproducible and accurate for determining DNA fragment size. The PCR-CGE-LIF was sensitive since a significant fluorescent signal was obtained at the minimum admixture level employed of 1% in meat mixtures. Thus, the PCR-CGE-LIF method established was useful for the detection of chicken or turkey in heat treated meat mixtures and may prove to be useful for the detection of poultry meat in pork processed products.