连续流动法同时测定污水中氨氮和总磷

采用连续流动分析法测定污水中氨氮、总磷的含量。比较了污水样品不同的稀释倍数对测定结果的影响。实验结果表明:氨氮和总磷的质量浓度在0.1~8 mg/L范围内线性良好,线性相关系数均为0.99997;测量结果的相对标准偏差分别为2.01%,0.84%(n=7);方法检出限分别为0.012,0.009 mg/L;质控样测量值均在标示值范围内;样品加标回收率为93.4%~101.1%。污水的洁净程度对测定结果影响较大。洁净度高的污水,直接测定与稀释后测定,测定值无显著性差异;而洁净度低的污水,直接测定与稀释后测定结果差异比较大。该法采用全谱直读CCD检测方式,灵敏度高,稳定性好,无光谱干扰,且支持氨氮和总磷同时测定,方便快捷,适合污水中氨氮和总磷的测定。     

微波消解测定水样中总磷

研究了以H2O2-HNO3为氧化剂，用微波消解测定水样中总磷的分析方法。通过正交试验选择合适的消解条件与氧化剂投入量，选择合适的显色酸度及测定波长，方法对自然水样测定平均相对标准偏差为3．3％，平均回收率为100．3%。     

连续流动分析仪测定环境水样中硝酸盐氮和亚硝酸盐氮

硝酸盐氮和亚硝酸盐氮是我国水源水和地表水测定项目的常用指标，我国2002年地表水和水源水的新规定，大量的环境水样要求在相应较短的时间内报出结果，这就要求快速而又准确的分析方法和仪器，以提高实验室内的自动化程度，适应国家新标准的要求。     

环境水样中总磷分析方法及仪器的研究进展

磷是生物不可或缺的营养元素之一,但由于人类活动影响,在地表水和近岸海水中总磷一直是主要污染指标.总磷测定通常分两步进行:一是将水样中各种不同形态的磷消解转化为可被检测的磷酸盐;二是测定消解后样品中的磷酸盐浓度.消解方法有硫酸-硝酸消解法、干法灰化法、微波辅助消解法、过硫酸钾-高温高压消解法、UV光氧化法等.测定方法包括...     

连续流动分析法测定杏仁中氰化物

建立连续流动仪测定杏仁中氰化物的分析方法.将杏仁样品在超声水解后冷藏2 h,离心10 min,滤液经正己烷萃取,过滤定容,加入氢氧化钠调节滤液pH,采用连续流动仪测定.氰化物的质量浓度在0～1.0 mg/L范围内与吸光度呈良好的线性关系,线性相关系数为0.9999,方法检出限为0.05 mg/kg.测定结果的相对标准偏...     

流动注射法同时测定海水中氨氮和磷酸盐

采用流动注射法同时测定海水中氨氮和磷酸盐的含量。在优化的试验条件下,氨氮和磷酸盐的线性范围分别为0.25 mg·L-1和0.30 mg·L-1以内,检出限(3S/N)分别为0.42μg·L-1和0.56μg·L-1。氨氮和磷酸盐加标回收率分别在85.0%~103%和86.7%~103%之间,测定值的相对标准偏差(n=6)分别在0.43%~5.3%和0~4.1%之间。方法用于分析标准物质,测定结果与分光光度法的结果一致。     

离子色谱法测定海产品中磷酸盐、焦磷酸盐、偏磷酸盐和总磷

建立了离子色谱法测定海产品中磷酸盐、焦磷酸盐、偏磷酸盐和总磷的分析方法。样品经100 mmol/L NaOH溶液浸提,固相萃取柱去除有机物、阳离子、中和OH~后用于海产品中磷酸盐、焦磷酸盐和偏磷酸盐的测定;样品经干灰化法消化,固相萃取柱净化后用于总磷测定。考察了提取溶液的pH、有机物和共存离子对测定结果的影响。该方法的线性范围为0.3～60 mg/L,检出限为2.1～2.3 mg/kg,相对标准偏差为1.6%～2.6%。海鱼和虾仁样品中目标物的加标回收率为81.8%～100.0%。该方法选择性好,灵敏度高,用于实际样品测定结果令人满意。     

微波消解测定环境水样中化学需氧量的研究

本文介绍了一种在密闭容器内，进行微波消解、快速测定环境水样中化学需氧量的新方法，并研究了微波功率、消解时间、酸等因素对分析结果的影响。对不同水样的化学需氧量进行了测定，与标准Ｋ２Ｃｒ２Ｏ７回流法相对照，大大提高了分析速度，用Ｆ检验法及ｔ－检验法检验，没有显著性差异。     

流动注射法测定环境水样中的铁(Ⅲ)

二甲酚橙和Fe(Ⅲ)在6×10-2 mol·L-1 HCl溶液中生成紫红色络合物,在558nm处有最大吸收峰。在最优的实验条件下,Fe(Ⅲ)线性范围0.01～2.5mg·L-1,y(mV)=235.74x+10.554(x为三价铁的浓度),相关系数R2=0.999,精密度相对标准偏差0.36%(n=15)。加标回收率在103.0%～106.5%范围内。与国标法相比误差在±5%之内。方法简单,操作简便,可在线快速测定环境水样中的Fe(Ⅲ)。     

连续流动分析法测定水中的阴离子表面活性剂

在GB/T 7494–1987法的基础上将自动进样、在线萃取、在线分离技术与分光光度法相结合,测定水中阴离子表面活性剂的含量。在分析过程中利用二次萃取和分离有效除去干扰物质,提高了分析的准确度和灵敏度。标准工作曲线线性相关系数为0.999 2,检出限为0.007 mg/L,测定结果的相对标准偏差为2.0%~2.4%(n=6),加标回收率为95.0%~98.0%。连续流动注射分析法操作简单,基线稳定速度快,连续分析效果好,大大降低了氯仿对人体的危害,适合大批量水质中阴离子表面活性剂含量的分析。     

流动注射分光光度法测定水体总磷

提出了一种单通道紫外消解流动注射比色分析法，能快速测定水样中总磷。实验采用了微量恒流混合泵、新型的细长型高灵敏度流通池及紫外消解器、液流分配阀、恒流瓶等FIA装置，并使用工业编程控制器和智能触摸屏进行控制和计算，使操作更为方便。此法分析时间短，测量范围宽，精度高，适合于各种水体的测定。     

紫外消解流动注射光度法测定海水养殖废水中总氮、总磷

采用紫外消解–流动注射分光光度法测定海水养殖废水中总氮和总磷。总氮样品浓度在0.050~5.00mg/L范围内,总磷样品浓度在0.020~5.00 mg/L范围内均与峰高有良好的线性关系(r分别为0.999 90和0.999 94)。在盐度为35,进样时间为70 s,清洗时间为90 s的条件下,总氮和总磷的检出限分别为0.050mg/L和0.020 mg/L,测定结果的相对标准偏差分别为1.15%,0.60%(n=6),加标回收率分别为98.7%~101.2%和98.6%~102.5%。该方法能满足海水养殖废水中总氮和总磷的监测要求。     

Determination of Nitrite,Phosphate, and Silicate by Valveless Continuous Analysis with a Bubble-Free Flow Cell and Spectrophotometric Detection

A continuous flow analysis system, composed of a 1.2-cm laboratory-made antibubble flow cell and a spectrophotometer, was established. The system was evaluated for the determination of nitrite, phosphate, and silicate. Different from flow injection analysis and other flow analysis modes, an injection or multiposition valve was not needed. Even better, the system was free from interferences from air bubbles without the use of a debubbler device or electronic bubble gate. Without the formation of air bubbles, the chemical reaction was accelerated using a water bath. The experimental parameters for nutrient analysis, including reagent concentration, flow strategy, flow rate, and reaction temperature, were optimized based on a univariate experimental design. The carry-over effect was comprehensively evaluated and may be ignored using this protocol. The established system and analytical methods were especially suitable for laboratories with only basic instruments and limited budgets. The system had the advantages of high sample throughput (>60?h^?1); great convenience without valve utilization; long linear dynamic ranges (0.2–80?µM for nitrite, 0.3–14?µM for phosphate, and 0.5–120?µM for silicate); low detection limits (0.06?µM for nitrite, 0.08?µM for phosphate, and 0.11?µM for silicate); and high recovery values (91.5?±?1.01 to 108.7?±?3.18%). In addition to water samples, national reference materials were analyzed, and the results were in good agreement with the certified values.     

微波消解-连续流动分析法测定肉类食品中的磷

肉类食品是重要的磷来源,随着磷酸盐在肉制品生产加工中的广泛应用,它在食品中的安全性也备受关注。因此,建立一种肉类食品中磷快速定量测定方法具有重要意义。通过优化肉类样品的微波消解体系,建立了肉类样品磷含量检测的微波消解-连续流动分析方法。研究结果表明,硝酸可以作为微波消解酸体系,证明硝酸用量为6 mL、样品量0.1 g、赶酸温度210℃和消解液稀释倍数100倍时,为较优的微波消解条件。微波消解处理后的样品利用连续流动分析仪进行外标法定量检测。测定结果表明,建立的微波消解-连续流动分析法的检测线性范围为0～4 mg/L,线性相关系数为0.999 4,样品回收率为92.5%～103%,相对标准偏差RSD小于5%(n=10)。方法适用于肉类食品中磷的快速、批量检测。     

Flow Injection Spectrophotometric Determination of Iodide in Environmental Samples

 An alternative and simple flow injection spectrophotometric analysis method for the determination of iodide in environmental samples is reported. The method is based on the catalytic destruction of the colour of the Fe(III)–SCN⁻–CP⁺–_nBP_y quarternary complex. The complex shows maximum absorption at 495 nm. The apparent molar absorptivity of the complex in terms of iodide is (6.22) × 10⁵ l mol⁻¹ cm⁻¹. The detection limit of the method is 0.1 ng ml⁻¹ of iodide. The method obeys Beer’s law up to 120 μg l⁻¹ with slope, intercept and correlation coefficient of 0.11, − 0.52 and + 0.99, respectively. Various flow injection analysis parameters for the determination of iodide in the environmental samples were optimized. The sample throughput of the method is 60 samples h⁻¹. The method was successfully useful for the determination of trace level of iodide in environmental samples i.e. ground, surface water. Received November 12, 2001; accepted April 2, 2002; published online July 22, 2002     

Multisyringe Flow Injection Analysis for Determination of 1-Naphthylamine in Water Samples

1-Naphthylamine (NPA) is one of the main degradation products of pesticides derived from naphthalene, and a well-known bladder carcinogen in men. The Griess assay is used for NPA determination because of its high sensitivity and selectivity. The azo dye 4-(sulphophenylazo)-1-naphthylamine is formed, which shows a peak maximum at 540 nm. After optimizing multisyringe flow injection analysis (MSFIA) parameters, the analytical characteristics of the method were obtained, with a working linear range of 0.5 to 14 mg L⁻¹, according to the equation A = 0.0738±0.0019 [NPA] + 0.0028 ± 0.0042, r = 0.9997. Values for RSD (%) and E_rel (%) were calculated for the concentration levels of 0.5, 6 and 12 mg L⁻¹; values obtained were 1.1, 0.4 and 0.3% for RSD and 0.8, 0.3 and 0.2% for E_rel, respectively. LD was 0.01 mg L⁻¹ and LQ was 0.04 mg L⁻¹ NPA. The MSFIA procedure for the determination of NPA was applied to different water samples (well water, tap water, seawater, and wastewater from the EDAR-1, Palma de Mallorca water treatment plant), with satisfactory results and a throughput of 90 samples per hour.