Verifying the geographical origin of poultry: The application of stable isotope and trace element (SITE) analysis

Stable isotope and elemental analysis, together with statistical processing of the resultant data has been used to determine the geographical origin of poultry and hence provide a means to verify poultry labels originating from major producing countries/regions. Multivariate statistical analysis has demonstrated that 18 variables, including carbon, hydrogen and nitrogen stable isotope ratios and elemental concentrations of magnesium, thallium, rubidium and molybdenum, are important parameters in poultry origin determination. Using cross-validated discriminant analysis 88.3% of poultry geographical origins were correctly classified (n = 339). Individual correct-classification rates were as follows; China, 100% (n = 36); Brazil, 94.1% (n = 101); Europe 92% (n = 87); Chile 82.6% (n = 46); Thailand, 70.3% (n = 46) and Argentina 50% (n = 10). The main identification errors were associated with miss-classification of Argentinean samples with those originating from Chile and Thailand. Carbon stable isotope ratios of chicken meat indicate the quantity of maize in the diet and this leads to useful discrimination between a large proportion of European poultry and poultry reared in locations such as South America, Thailand and China where maize feeding predominates. The use of poultry carbon isotope values as a simple ‘screening’ parameter to differentiate European poultry meat from other major importers is not as reliable as for the differentiation of European and South American beef. However carbon isotope ratios will be useful in most instances to corroborate suspicion of mislabelling of non corn-fed European poultry. The stable isotopes of hydrogen and oxygen in chicken meat change in a similar way to surface waters around the globe. Our findings support the hypothesis that the global isotopic variation of stable isotopes in drinking water and feed are transferred into animal tissue and can be used to help establish an animal's geographic origin. This is a significant finding and mirrors our observations for beef skeletal muscle δ²H ‰ and δ¹⁸O ‰ values. These systematic variations can be exploited to give a ‘low-resolution’ indication of an animal's geographic origin (e.g. Northern Europe versus the tropics).     

Towards the development of a multi-element analysis by ICP-oa-TOF-MS for tracing the geographical origin of processed tomato products

In this preliminary work, the mineral composition (Li, Be, Al, V, Cr, Mn, Co, Cu, Zn, Ga, As, Rb, Sr, Ag, Cd, In, Cs, Ba, Tl, Pb, Bi, and U) of forty-one processed tomato samples, coming from three different countries (Italy, China and Spain), was investigated by Inductively Coupled Plasma orthogonal acceleration Time-of-Flight Mass Spectrometer (ICP-oa-TOF-MS), exploiting the characteristic of simultaneity of the measurements that is distinctive of this type of instrument. The large amount of data achieved through multi-element analysis was statistically processed by Linear Discriminant Analysis (LDA), and a good geographical origin discrimination of tomato samples (99.9% of cases correctly classified) was obtained. Li and Sr could distinguish Chinese from EU samples, while Co and Cu were able to differentiate Spanish tomato from the other ones. Moreover some elemental ratios (Li/Cr, Mn/Cu, Co/Cu and Sr/Cd) allowed a better clusters separation than single elements.The work is still in progress, but preliminary results indicates that ICP-oa-TOF-MS could be considered a fast, precise and accurate instrument for multi-element determinations to be used for tracing tomato provenance.     

塔里木盆地中央隆起带：新元古代造山型基底拼合带——来自深钻孔的碎屑记录证据

在塔里木盆地巴楚隆起,新近有同1井、夏河1井和巴探5井在寒武系碳酸盐岩之下钻遇碎屑沉积岩。在对碎屑岩进行详细岩相学观测、碎屑组分统计和地球化学分析的基础上,深入探讨了碎屑岩源区及其形成的构造环境。砾岩和砂岩碎屑组成与泥岩地球化学特征共同表明,这3口井寒武系碳酸盐岩之下的碎屑岩物源区包括沉积岩、火成岩和变质岩,以中酸性火山岩和侵入岩为主。砾石及砂岩中碎屑颗粒棱角状-次圆状的外貌、砾石中易磨蚀风化组分（碳酸盐岩和片岩）的存在以及泥岩较低的Th/U比值都反映这些碎屑岩为成熟度较低的近源堆积物。通过碎屑成分、地球化学特征和碎屑锆石年龄结构对比,确定这些碎屑岩的碎屑组分主要源自其下伏基底。砾岩和砂岩碎屑模式、泥岩地球化学特征及碎屑锆石原位微量元素分析结果表明,碎屑源区（即下伏基底）在新元古代（峰期约790~730 Ma）处于大陆边缘弧构造环境。本文新获取的碎屑记录证据与前人对同1井底安山岩、英安岩及卡塔克隆起上塔参1井底闪长岩、花岗闪长岩形成时代及构造环境的研究结论完全一致,表明横亘塔里木盆地中部的中央隆起带是一条新元古代大陆边缘弧,塔里木盆地的基底是由新元古代造山作用形成的拼合基底。     

巴楚隆起先巴扎三维区鹰山组岩溶特征及成因

巴楚隆起西部剥蚀区先巴扎三维区鹰山组在加里东中期长期暴露地表接受大气淡水淋滤发生岩溶作用。以加里东中期岩溶古地貌为基础,结合精细相干和地震属性分析,对研究区古水系进行精细刻画,类比研究区与西克尔露头的岩溶特征,总结造成这种岩溶特征的成因。研究区地表各水系从干流到分支河谷发育且成熟而稳定,树枝状水系发育,表明该区具有丰富的大气淡水补给和良好的岩性-构造条件,地表岩溶相当发育;而地下水系主要以地表主干水系为排泄基面,其基本围绕地表水系分布且分支少,说明地下水没有形成系统的水文网络,地下岩溶的发育受到一定限制。研究区缺乏良好的径流和排泄系统,岩溶洞穴分布有限,以孤立分散洞穴为主,很少发育大的洞穴或暗河。地下岩溶发育程度低的原因包括岩溶发育不彻底、洞穴充填和溶蚀孔洞层发育。     

川西坳陷须家河组致密砂岩储层裂缝发育特征及其成因——以孝泉-新场-合兴场地区为例

川西坳陷孝泉-新场-合兴场地区上三叠统须家河组储层具有埋藏深、致密、低孔隙度、低渗透率的特点,裂缝的发育程度对储层具有重要的意义。为此,通过岩心观察和显微镜下薄片鉴定,研究了裂缝的发育类型、发育密度、发育频率以及充填特征。结果表明：储层中以低角度裂缝发育为主,高角度裂缝欠发育;微裂缝对须二段储集空间的影响显著大于须四段,在须二段地层中,对储层渗透率有实质性影响的主要是一些相对宏观的裂缝。综合区域地质背景及前人的研究成果,认为差异压实导致的非构造作用是该区裂缝尤其是须二段裂缝形成的主要机制,但后期燕山、喜山构造运动产生的构造应力都可能叠加在原有的非构造成因的裂缝上,使之具有构造成因色彩。     

甲醇氧化制二甲氧基甲烷液体产物的气相色谱分析

针对甲醇选择氧化制二甲氧基甲烷过程的反应物和产物,比较了甲醇、水、甲酸甲酯、二甲氧基甲烷、甲醛等物质在不同色谱填充柱上的分离效率,确定了其校正曲线,建立了系统的甲醇选择氧化制二甲氧基甲烷反应混合物的定量气相色谱分析方法。该分析方法操作简单,准确度高。     

基于最小偏移距分选的地震数据采集质量监控新方法——以沙特Berri工区三维项目为例

在海陆过渡带三维勘探项目的野外施工过程中,通常采用常规的线性动校正或直接核对炮点的方法来检查单炮是否发生偏移,但是,这种监控手段工作效率低下且监控质量得不到保证。介绍了一种基于最小偏移距分选的地震数据采集质量监控方法,基本原理是:将初至拉平,观察是否存在初至起跳异常,从而确定是否存在炮点偏移。在沙特Berri工区三维地震数据采集过程中,首先在放炮时采用GPS导航系统,在导航系统监控软件界面上监测炮点偏移情况,初步控制炮点误差;然后利用基于最小偏移距分选方法对地震数据采集质量进行监控,并对炮点和检波点偏移误差进行分析和检查。应用结果表明该方法能精确地检查炮点和检波点偏移情况,有效地提高了地震资料采集质量。     

基于砂地比的复合河道沉积期次空间解析方法——以鄂尔多斯盆地苏里格气田ST密井网试验区盒8下(2)为例

在对鄂尔多斯盆地苏里格气田储层精细描述研究过程中,经常遇到井间砂体尖灭位置无法判定的情况,这对砂体规模定量表征带来很大困难。为此,在精细综合地质研究基础上,形成了一套快速、定量确定单期河道边界尖灭位置的方法,利用砂地比确定不同期数河道叠置范围,并在此平面约束下,分析剖面位置多期河道组合情况,进而刻画复合河道在三维空间的展布特征。以苏里格气田ST区块密井网试验区二叠系中统下石盒子组盒8^下（2）小层为应用实例,结果表明：①小层细分为n个基本等厚的单层,i期叠置区域砂地比范围为（i-1）/n~i/n;②河道下切侵蚀、河道边缘砂体厚度变薄,可能造成局部解释叠置区域偏差,应对该区域进行适当调整,但不影响方法的整体适用性。该方法能够快速确定各单层河道空间展布范围,为储层定量表征和有利区预测提供技术支撑。