小麦籽粒中微量铅的快速测定技术(简报)

为建立一种快速测定粮食中微量铅的新方法,以南阳彩色小麦为材料,用微波压力消解技术快速处理样品,对测定条件进行优化,并与国家颁布标准方法(GB/T5009.12-2003)进行比较。结果表明:加标回收率为92.5%～96.8%,相对标准偏差RSD(Relative Standard Deviation)为0.67%～1.7%(n=11),铅的最低检出限为0.0099mg/L,测定的线性范围为0.850～206.0mg/L,相关系数为0.996,电极斜率为24.160。样品用该法与国标方法对照测定并进行显著性检验证明,该方法具有直观、快速、简便、灵敏、准确、适于现场进行测定的显著优点。     

全固态他莫昔芬选择电极的研制与应用

首次报道了一种以拘橼酸他莫昔芬与浓氢溴酸反应生成的衍生物的碘化物与碘化 的缔合物为电活性物的全固态他莫昔芬选择电极，电极的线性响应范围为１．０×１０－２～１０×１０－５ｍｏｌ／Ｌ斜率为４８ｍＶ／ｐＣ，检测限为８．０× １０－６ｍｏｌ／Ｌ，此电极响应迅速，重视性好，用此电极以标准曲线法对药物中的他莫昔芬进行了测定，此法简便，结果与分光光度法相符。     

高压静电场解冻机理分析

为了探索高压静电场解冻机理,优化解冻工艺,提高解冻效率,通过采用针电极、线电极和板电极在不同的电压下对冰进行了解冻速度对比试验,同时进行了针电极下冰加玻璃罩与不加罩的解冻速度对比试验和线电极下电极间距（电压）、线间距对解冻速度的影响试验。试验结果表明：采用板电极解冻效果不明显,而采用线电极和针电极能获得较大的解冻速度,加玻璃罩后冰的解冻速度明显低于未加罩冰的解冻速度,上下电极间距（电压）和线间距也都对解冻速度有一定影响,最后分析了解冻机理,认为离子风对冰的冲击作用是导致解冻速度增加的主要原因。     

标准加入直读法快速测定南阳彩色小麦面粉中硝酸根的研究

为了建立一种快速测定小麦面粉中硝酸根的新方法,以南阳彩色小麦为材料,用微波快速浸提样品,与超声波浸提法对照,用离子选择性电极标准加入———浓度直读法快速测定样品中的硝酸根,并进行了测定条件的优化。结果表明:用二次重复加入标准溶液的方法,测定的回收率为89.5%~102.0%。测定结果的相对标准偏差RSD为2.8%~4.7%(n=11),硝酸根的最低检出限为0.040 mg.L-1,测定的线性范围为0.100~100.0 mg.L-1,相关系数为0.997。该方法具有直观、快速、简便、灵敏、准确、适于现场进行测定的显著优点,结果令人满意。     

基于电化学和虚拟仪器的土壤重金属检测系统研究

采用超声波辅助提取法对土壤样本进行快速前处理,以铋膜修饰丝网印刷电极作为传感器,结合差分脉冲阳极溶出伏安法对土壤浸提液中的铅和镉进行精确测量。检测仪器以Lab View平台软件为工作核心,结合MSP430单片机、恒电位电路、I/V转换电路、电磁阀和蠕动泵等硬件设备实现了对土壤浸提液的自动进样、电化学分析以及排液清洗等铅和镉的操作。针对实际土壤样本测量时可能产生的误差,分别采用了概率统计算法以及多次标准添加法加以消除。系统检测限分别达到2.6μg/L和1.8μg/L。对不同地区采集到的多个土壤样本进行分析,结果表明该系统具有检测精度高、重现性好、速度快、功耗低等优点,适合对农田土壤重金属进行快速检测和评估。     

Validation of the Nova CRT8 for the measurement of ionized magnesium in feline serum

Background: Evaluation of serum magnesium (Mg) concentration is becoming important in human and veterinary critical care medicine. An ion‐selective electrode can measure the physiologically active ionized fraction. Objectives: The purpose of this study was to validate an ion‐specific electrode analyzer and assay for measuring ionized Mg in feline serum and to determine a reference interval for this analyte in cats. Methods: Venous blood samples were collected anaerobically from clinically healthy cats, and the serum was used to validate the analyzer and assay. This included investigating the stability of samples stored at different temperatures, intra‐ and interassay precision, linearity, analytical sensitivity, and potential interferences from bilirubin, lipemia, hemoglobin, or serum separator tubes. A reference interval was calculated. Results: Serum samples evaluated for ionized Mg concentrations can be stored at 20°C for ≤24 hours, at 4°C for ≤72 hours, and at ?20°C for ≤4 weeks, when samples are minimally exposed to air. Intra‐ and interassay precisions had coefficients of variation (CVs) of 1.23% and 2.02%, respectively. There was good linearity using serum (r= .998; y=?0.0057 + 1.0256x) and manufacturer‐supplied aqueous solutions and quality control materials (r= .999; y= 0.0110 + 0.9213x). Apparent analytical sensitivity was at least 0.015 mmol/L. Mean recovery was good for ionized Mg in samples with ≤1+ icterus (104%), 4+ lipemia (99.3%) and 1–4+ hemolysis (98.6%). There was no significant difference (P= .52) in ionized Mg concentrations in serum collected in tubes containing no additives compared with serum collected in glass separator tubes. The serum ionized Mg reference interval was 0.47–0.63 mmol/L (n = 40). Conclusions: The Nova CRT8 analyzer and assay provide a precise and reliable method of measuring ionized Mg concentration in feline serum. Strict adherence to sampling techniques, handling, and storage are necessary for reliable results.     

Validation of 2 techniques for electrocardiographic recording in dogs and cats

BACKGROUND: Standard electrocardiographic (ECG) recording in the dog and cat is commonly performed in right lateral recumbency, by connecting the ECG leads to the skin of the patient via metallic alligator clips. The jaws of the alligator clips are usually filed or flattened to reduce their uncomfortable pressure on the patient's skin. However, filed and flattened alligator clips can occasionally lose their grip to the skin, causing lead detachment during standard ECG recording. HYPOTHESIS: The aim of the study was to validate two novel ECG recording techniques ("gel" and "pads"). ANIMALS: Six-lead standard ECG recording was obtained from 42 dogs and 40 cats using the standard technique, as well as the two novel methods. METHODS: Measurements were taken of the amplitude and duration of P waves and QRS complexes, duration of PQ and QT intervals, and mean electrical axis (MEA). In each recording, five representative complexes were measured, and the results were averaged for each parameter. RESULTS: A good quality ECG recording was obtained with all the three different techniques, although a degree of wandering trace was observed in one third of cats with the "pads" technique. Bland-Altman analysis showed good agreement between the ECG values recorded with the two novel techniques and those recorded with the standard traditional technique. Furthermore, the observed differences were not clinically relevant, except for the R wave amplitude recorded with the "pads" method in cats (-0.35 to 0.37 mV). CONCLUSIONS AND CLINICAL IMPORTANCE: In conclusion, this study supports the reliability and clinical validity of the "gel" and "pads" techniques for ECG recording both in the dog and the cat, with some limitations for the "pads" technique in cats.     

离子选择微电极与膜片钳在电生理检测中的应用

玻璃微电极在检测植物细胞内部的电生理活动中有着重要的作用.根据检测目的的不同,微电极主要应用可以分为离子选择微电极检测技术和膜片钳技术.为此,介绍了二者的检测原理,对离子选择微电极技术和膜片钳技术在检测植物细胞电生理信息方面的应用做了详细的论述,并对其以后的应用与发展进行了展望.     

Measurement of pH at the root surface of red clover (Trifolium pratense) grown in soils differing in proton buffer capacity

Summary Measurements of pH were made at the root surface of Trifolium pratense, using Sb electrodes. Nodulated plants were grown in rhizotrones on a sandy soil free of carbonate and on a clay soil rich in carbonate. In the sandy soil, pH at the surface of root laterals was about 1 unit lower than in the bulk soil. The lowest pH values were found at the root tips. In the calcareous soil, pH measured at the root surface did not differ from pH in the bulk soil. This soil had a much higher H⁺ buffer capacity than the sandy soils. It seems likely that H⁺ ions excreted from the roots grown in the calcareous soil were directly neutralized by soil carbonate.