Proficiency testing on the analytical control of precious metal production

Our experience of executing proficiency testing programs on the analysis of precious metals and precious metal bearing materials is summarized. Six proficiency testing programs of the ”distributed sample testing” type were carried out using samples essentially distinct from each other: (I) certified samples of fine gold and fine silver, and (II) recoverable raw (scrap and catalyst waste) containing precious metals of unknown contents. The test results were assessed using the London Bullion Market Association (LBMA) rules and by Z-criteria using the ISO/IEC Guide 43 scale. Satisfactory results were presented by all participants for the analysis of certified samples of fine gold and fine silver. The results of catalyst waste analysis agreed rather well, whereas the scrap analysis revealed an essential discrepancy in the data for some samples. The reasons for such discrepancies are discussed. Received: 9 June 2000 Accepted: 21 November 2000     

子窗口分析法用于偶氮染料GC-MS重叠峰的解析

 将子窗口因子分析法 (SWFA)应用于GC MS联用检测数据分析 ,并以两种偶氮染料 3,3′ 二氯联苯胺和 4,4′ 次甲基 双 (2 氯苯胺 )重叠图谱为例进行了解析。结果表明 ,此方法可直接进行目标组分的质谱分辨 ,得到目标组分的质谱图 ,进而得到该组分的色谱图。其结果准确、可靠。与窗口因子分析相比 ,子窗口的选择更加容易 ,人工干预少 ,解析速度快。     

统计质量保证技术在分析测试实验室内部质量控制中的应用

对通过统计质量保证（SQA）技术进行分析测试实验室内部质量控制（IQC）的方法作了初探。研究结果表明,SQA技术的应用能保证实验室始终处于统计受控状态,确保测试数据的有效性,有利于分析测试实验室质量保证活动的开展。     

Preliminary Evaluation of Supercritical Carbon Dioxide Extracted Dabai Pulp Oleoresin as a New Alternative Fat

There has been growing interest among food scientists in producing a toxin-free fat as an end product with varying physical or nutritional properties of interest to the food industry. Oleoresin is a rich source of bioactive compounds which consumers can easily add to a large variety of food. Dabai (Canarium odontophyllum) pulp oleoresin (DPL) was extracted using supercritical carbon dioxide (SC-CO₂) extraction, a green extraction technology. This study investigates the quality of SC-CO₂ extracted DPL in discovering its potential as a new alternative fat. The extraction experiment was carried out at a pressure of 40 MPa and a temperature of 40 °C. DPL is a saturated fatty acid (SFA)-rich fat due to its high SFA composition (47.72 ± 0.01%). In addition, the low content of peroxide value (PV) (5.60 ± 0.09 mEq/kg) and free fatty acids (FFA) (3.40 ± 0.03%) indicate the quality and stability of DPL for various applications besides food consumption. DPL also has a low slip melting point (SMP) (20.20 ± 0.03 °C), and HPLC-FID revealed that DPL contained 0.13 ± 0.02 mg/100 g of vitamin E (α-tocopherol), indicating its potential application as a solid fat with a bioactive compound. This present work demonstrates the possible prospect of DPL in the formulation of end products for food industries.     

Wavelet-Fourier self-deconvolution

Using a wavelet function as the filter function of Fourier self-deconvolution, a new method of resolving overlapped peaks, wavelet-Fourier self-deconvolution, is founded. The properties of different wavelet deconvolution functions are studied. In addition, a cutoff value coefficient method of eliminating artificial peaks and wavelet method of removing shoulder peaks using the ratio of maximum peak to minimum peak is established. As a result, some problems in classical Fourier self-deconvolution are solved, such as the bad result of denoising, complicated processing, as well as usual appearance of artificial and shoulder peaks. Wavelet-Fourier self-deconvolution is applied to determination of multi-components in oscillographic chronopotentiometry. Experimental results show that the method has characteristics of simpler process and better effect of processing.     

清江水布垭水电站地下厂房岩体质量评价及反馈设计研究

考虑地下水 ,地应力及结构面产状和岩溶、剪切带发育的特点修正 ,确定了水布垭水电站地下工程洞室工程岩体质量 ,进行了地下工程的 RMR分类研究 ,讨论了与水布垭地下工程反馈设计及信息法施工的有关问题。     

关于M21激光束的分析

对实验上和理论上出现的Ｍ＾２〈１激光束作了综述,并进行了分析与研究,发现真正可行、实用的Ｍ＾２〈１激光束只有由点光源经尾部控制衍射在中央输出经轴上相博士干叠加成新谓的余弦－高斯光束。     

Sense and nonsense of quality assurance in an R&D environment

Quality has always been one of the key issues in laboratories in general and formal quality assurance (QA) in testing laboratories has gained popularity over the last decade. However, the implementation QA in research and development (R&;D) laboratories is still the domain of a few pioneers. We can even ask whether a QA system in research makes sense at all and if such a system really provides any added value? Difficulties with respect to the implementation of such a system are mainly associated with the nature of the research process itself. However, it is obvious that QA offers clear advantages in R&;D, if some critical success factors have been taken into account. An important issue is the selection of a good QA standard for R&;D. This is certainly not an easy task, since there are no specific standards. Fortunately, some useful international guides have been published recently.     

一种有效提取弱信号的新方法

随机共振 ( Stochastic Resonance,简称 SR)最初由 Benzi[1] 于 1 981年提出 ,并在气象学领域中得到了成功的应用 .根据随机共振理论 ,通过加噪声可在某一“共振”点处大幅度提高信号的信噪比 .这种方法也已成功地应用于方波脉冲信号的恢复 [2 ] ,但在化学信号中的应用尚属空白 .我们首次将这种方法用于化学弱信号的检测 ,并在简单喇曼谱图的解析中获得成功 [3 ] .但是 ,加噪声的方法作为一种有效的信号分析手段还显得很不成熟 .具体表现为处理过程较繁 ,分析信号的峰位偏移明显 ,而且结果在一定程度上要依赖人为判断来决定 [3 ] .　　在…     

清开灵注射液生产过程中金银花提取液的在线质量控制方法研究

为建立清开灵注射液生产过程中的中间体金银花提取液快速准确的在线质量控制方法, 通过对金银花提取液的UV原始光谱、一阶导数光谱进行波长点的数据筛选,选择与HPLC法测得的绿原酸含量相关性最好的光谱类型和波长点进行建模,建立绿原酸含量的UV预测方程。另取10批金银花提取液检验预测结果的可靠性。UV原始光谱中最佳波长为294 nm(r=0.991 9,n=28);一阶导数光谱中最佳波长为316 nm(r=0.995 9,n=28)。绿原酸含量的预测方程为：c(mg·mL-1)＝506.254 3×A_{316 nm}＋0.177 1。经检验,预测方程准确、可靠(r=0.997 1,n=10),可直接应用于在线检测。绿原酸含量的预测结果为：约90％的金银花提取液中绿原酸含量分布为0.4～4.0 mg·mL-1。此法简单、快速、准确,可作为清开灵注射液生产过程中金银花提取液的在线质量控制方法。