取代基物化参数及其在药物定量构效关系中的应用

把取代基电性、立体及疏水性物化参数组合建立一种新取代基描述方法, 对环尿素类和N,N-二甲基-2-溴苯乙胺类衍生物进行结构表征. 对训练样本集通过逐步回归筛选变量, 所建多元线性回归方程R2分别为0.853和0.960, 留一法交互检验Rcv2分别为0.723和0.901；用预测集样本作外部预测, 所得Qext2分别为0.7617和0.7653. 结果显示：环尿素类化合物结构中苯环邻位立体、间位疏水、对位疏水及立体因素对该类药物抗HIV活性产生阻抑作用； N,N-二甲基-2-溴苯乙胺类苯环上取代基立体因素及对位给电子效应有利于提高肾上腺素能阻断活性.     

Rapid test strips for analysis of mycotoxins in food and feed

An overview is given on recent trends and applications of rapid immunodiagnostic tests for screening of food and feed for mycotoxins. Different test formats are discussed, and challenges in the development of lateral-flow devices for on-site determination of mycotoxins, with requirements such as being robust, fast, and cost-effective, are briefly elucidated.     

Quantitative Determination by Using HPLC and GLC Methods for Cocaine HCl in Synthetic Binary Mixtures with Procaine HCl,Lidocaine HCl and Caffeine

ABSTRACT

Cocaine HCl is a substance which creates psychological and physical dependence. Usually it is available on the market being diluted by other substances, like local anesthetics, analeptics and CNS stimulating agents and inert substance.

In this study, HPLC and GLC methods were applied for qualitative and quantitative determinations of synthetic binary mixtures. In the HPLC determination, μ Bondopack C₁₈ 10 μm. column system, a mobile phase consisting of methanol-water-phosphoric acid-1% hexylamine (75:175:250:3,5) and U.V. detection by photodiodearray (196–600 nm) were used.

The linear concentration areas were found in a range of 2.5–25 μg/mL. The R.S.D percentages for cocaine HCl, procaine HCl, lidocaine HCl and caffeine were found as 0.922, 0.568, 1.18 and 1.04, respectively.

In the GLC determination, two different column systems, a 2% OV-17-Gas Chrom W-HP 100–200 mesh filled column and a 0.25 SE-52 fused silica capillary column, were used. Nitrogen was used in a filled column and helium was used in a capillary column. Mobile phase flow rates were set as 30 mL/min and a flame ionization detector was used with both column systems.

The linear concentration intervals were found in a range of 2–25 μL/mL in both methods. The R.S.D. for cocaine HCl, procaine HCl, lidocaine HCl, and caffeine were found to be 0.907, 0.948, 0.770, 0.901 in the filled column. For cocaine HCl, procaine HCl and caffeine R.S.D.'s of 0.774, 0.809, 0.814 were found, when a capillary column was used. In quantitative determinations, antipyrine was chosen as internal standard in the HPLC and GLC methods.     

Validation of the Tessier scheme for speciation of metals in soil using the Bland and Altman test

The Tessier extraction method was used for speciation of Cu, Pb, Zn, As, Fe and Mn in a large concentration range in contaminated soil with various mineralogical compositions. The results were compared by X-ray fluorescence spectrometry (XRF) as a reference method using the Bland and Altman test. A sum of five fractions (exchangeable, bound to carbonates, Fe-Mn oxides, organic matter and residual forms) was compared with the total content determined on solid matrix by the reference method. A good agreement between the methods in the whole concentration range was found for Cu, Zn, As, and Fe. For Mn and Pb, XRF was found suitable to verify the sequential extraction only for concentrations above 250 mg kg⁻¹. This was a consequence of a poorer reproducibility of Pb extraction using the Tessier scheme due to a great difference in the mineralogical composition and the diversity of the Pb species identified in soil. The poorer result of Mn was attributed to the spectral interference of Fe in XRF. Presented at the 34th International Conference of the Slovak Society of Chemical Engineering, Tatranské Matliare, 21–25 May 2007.     

鸡蛋中氟虫腈砜能力验证样品单元内与单元间均匀性评价案例与模型分析

对鸡蛋中氟虫腈砜能力验证样品进行单元内均匀性和单元间均匀性评价。对能力验证涉及的检测方法进行方法学考察,按照预设的模型,在单元内和单元间取样检测。使用单元内子样结果均方差和方法重复性均方差构建单因素方差分析模型,完成了单元内均匀性评价。对单元间和单元内均匀性评价的方差分析模型中组间和组内方差的来源及代表性进行了讨论。结果表明鸡蛋中氟虫腈砜样品的单元内均匀性和单元间均匀性满足要求。开展单元内均匀性评价有利于掌握能力验证方法性能,确认检测最小取样量,识别不均匀性来源,增加单元间均匀性评价的可靠性。建立的单元内均匀性评价模型克服了标准模型中多次转化测量数据难以获得的问题,可在各类能力验证项目中推广应用。     

Rapid,Quantitative, and Ultrasensitive Point‐of‐Care Testing: A Portable SERS Reader for Lateral Flow Assays in Clinical Chemistry

The design of a portable Raman/SERS‐LFA reader with line illumination using a custom‐made fiber optic probe for rapid, quantitative, and ultrasensitive point‐of‐care testing (POCT) is presented. The pregnancy hormone human chorionic gonadotropin (hCG) is detectable in clinical samples within only 2–5 s down to approximately 1.6 mIU mL^?1. This acquisition time is several orders of magnitude shorter than those of existing approaches requiring expensive Raman instrumentation, and the method is 15‐times more sensitive than a commercially available lateral flow assay (LFA) as the gold standard. The SERS‐LFA technology paves the way for affordable, quantitative, and ultrasensitive POCT with multiplexing potential in real‐world applications, ranging from clinical chemistry to food and environmental analysis as well as drug and biowarfare agent testing.     

A competitive immunoassay for ultrasensitive detection of Hg in water,human serum and urine samples using immunochromatographic test based on surface-enhanced Raman scattering

An immunochromatographic test (ICT) strip was developed for ultrasensitive competitive immunoassay of Hg²⁺. This strategy was achieved by combining the easy-operation and rapidity of ICT with the high sensitivity of surface-enhanced Raman scattering (SERS). Monoclonal antibody (mAb) against Hg²⁺ and Raman active substance 4-mercaptobenzoic acid (MBA) dual labelled gold nanoparticles (GNPs) were prepared as an immunoprobe. The Raman scattering intensity of MBA on the test line of the ICT strip was measured for quantitative determination of Hg²⁺. The ICT was able to directly detect Hg²⁺ without complexing due to the specific recognition of the mAb with Hg²⁺. The IC₅₀ and limit of detection (LOD) of the assay for Hg²⁺ detection were 0.12 ng mL⁻¹ and 0.45 pg mL⁻¹, respectively. There was no cross-reactivity (CR) of the assay with other nineteen ions and the ICT strips could be kept for 5 weeks without loss of activity. The recoveries of the assay for water, human serum and urine samples spiked with Hg²⁺ were in range of 88.3–107.3% with the relative standard deviations (RSD) of 1.5–9.5% (n = 3). The proposed ICT was used for the detection of Hg²⁺ in urine samples collected from Occupational Disease Hospital and the results were confirmed by cold-vapor atomic fluorescence spectroscopy (CV-AFS). The assay exhibited high sensitivity, selectivity, stability, precision and accuracy, demonstrating a promising method for the detection of trace amount of Hg²⁺ in environmental water samples and biological serum and urine samples.     

Different approaches to legal requirements on validation of test methods for official control of foodstuffs and of veterinary drug residues and element contaminants in the EC

 In order to ensure food consumer protection as well as to avoid barriers to trade and unnecessary duplications of laboratory tests and to gain mutual recognition of results of analyses, the quality of laboratories and test results has to be guaranteed. For this purpose, the EC Council and the Commission have introducedprovisions – on measures for quality assurance for official laboratories concerning the analyses of foodstuffs on the one hand and animals and fresh meat on the other, – on the validation of test methods to obtain results of sufficient accuracy. This article deals with legal requirements in the European Union on basic principles of laboratory quality assurance for official notification to the EC Commission and on method validation concerning official laboratories. Widespread discussions and activities on measurement uncertainty are in progress, and the European validation standards for official purposes may serve as a basis for world-wide efforts on quality harmonization of analytical results. Although much time has already been spent, definitions and requirements have to be revised and further additions have to be made.     

Combining the least correlation design, wavelet packet transform and correlation coefficient test to reduce the size of calibration set for NIR quantitative analysis in multi-component systems

The paper focuses on solving a common and important problem of NIR quantitative analysis in multi-component systems: how to significantly reduce the size of the calibration set while not impairing the predictive precision. To cope with the problem orthogonal discrete wavelet packet transform (WPT), the least correlation design and correlation coefficient test (r-test) have been combined together. As three examples, a two-component carbon tetrachloride system with 21 calibration samples, a two-component aqueous system with 21 calibration samples, and a two-component aqueous system with 41 calibration samples have been treated with the proposed strategy, respectively. In comparison with some previous methods based on much more calibration samples, the results out of the strategy showed that the predictive ability was not obviously decreased for the first system while being clearly strengthened for the second one, and the predictive precision out of the third one was even satisfactory enough for most cases of quantitative analysis. In addition, all important factors and parameters related to our strategy are discussed in detail.