悬浮液进样-火焰原子光谱法测定烟叶中的钾锰

用悬浮液技术处理烟叶样品 ,即将样品烘干、粉碎、过筛 ,并悬浮在 1 .5g L琼脂溶液中制成均匀的悬浮液。以钙作为锰的释放剂和以钡作为钾的消电离剂。用工作曲线法测定 ,以火焰原子发射法 (FAES)测定钾 ,以火焰原子吸收法 (FAAS)测定锰。建立了快速测定烟叶中钾、锰的FAS法。对化学干扰、介质的影响及检出限进行了考察。测定结果的相对标准偏差 <2 .4% ,测定结果与灰化法一致 ,相对误差 <± 2 .5 %。     

悬浮进样原子吸收法测定茶叶中的微量元素

用悬浮液技术处理茶叶样品,即将样品烘干、粉碎、过筛,并悬浮在1.5g/L琼脂溶液中制成均匀的悬浮液,建立了火焰原子吸收快速测定茶叶中微量元素的方法。该法快捷、简便、具有良好的精密度和准确度,应用于实际样品的测定结果满意。     

火焰原子吸收光谱法测定预混合饲料及浓缩饲料中的高含量锰

以锰280．1nm次灵敏线作为分析谱线，用原子吸收光谱法测定预混合饲料和浓缩饲料中的高含量锰。锰的线性范围为0～12μg／mL，相关系数r=0．9994，相对标准偏差小于l％，回收率为97％～102％。该方法的测定结果与常规灵敏线原子吸收光谱法的测定结果基本一致。     

次灵敏线火焰原子吸收光谱法测定镍镁合金中镁

以镁的202.5nm次灵敏线为分析线,火焰原子吸收光谱法测定镍镁合金中的镁含量。样品以硝酸(1+1)溶解,采用氯化锶为释放剂,以消除共存元素的干扰。在优化的实验条件下,方法的相对标准偏差小于3%,样品加标回收率为95.0%～105.5%。结果表明采用镁的次灵敏线测定镍镁合金中的镁含量,其精密度和准确度均能达到分析要求,可满足日常检测的需求。     

Determination of Iron, Zinc and Calcium in Chinese Medicinal Herb by Suspension Sampling

将悬浮液进样技术应用于火焰原子吸收光谱法,建立了中草药中微量元素的快速分析新方法。将样品粉碎、悬浮在琼脂胶体中制成悬浮液;取适量样品悬浮液配制成试液,喷入空气－乙炔火焰,用标准加入法测定。用该法成功地测定了当归、川芎及川乌中的铁、锌、钙,测定结果与灰化法一致,方法简便、快速、准确。     

中草药中铁锌钙的悬浮液进样-火焰原子吸收光谱法测定

将悬浮液进样技术应用于火焰原子吸收光谱法, 建立了中草药中微量元素的快速分析新方法。将样品粉碎、悬浮在琼脂胶体中制成悬浮液; 取适量样品悬浮液配制成试液, 喷入空气－ 乙炔火焰, 用标准加入法测定。 用该法成功地测定了当归、川芎及川乌中的铁、锌、钙, 测定结果与灰化法一致, 方法简便、快速、准确。     

微波消解-原子吸收光谱法对海带中6种金属元素的测定

目的建立海带中6种金属元素的火焰原子吸收测定方法。方法利用微波消解处理海带样品,使用火焰原子吸收法测定海带中钙、镁、铁、锌、铜和锰。结果海带中含有丰富的金属元素,实验回收率为95.5%~108.2%,样品进行5次平行测定,RSD为1.22%~4.25%。结论该法具有快速、简便、灵敏、准确的优点,适用于海带中6种金属元素的测定。     

微波消解-原子光谱吸收法测定皮蛋中的六种营养元素

目的建立了皮蛋中6种营养元素的火焰原子吸收测定方法。方法利用微波消解处理样品,火焰原子吸收法测定皮蛋蛋白和皮蛋蛋黄中钙、镁、铁、锌、铜和锰。结果皮蛋中含量丰富的营养元素,回收率为97.2％～110.0％,样品进行5次平行测定,RSD为1.87％～5.61％。结论方法具有快速、简便、灵敏、准确的优点,适于皮蛋中6种营养元素的测定。     

非完全消化—悬浮液进样—火焰原子光谱法测定蘑菇中钾、镁、锌

将非完全消化法与悬浮液进样技术相合处理蘑菇样品，即先用浓HNO3低温消解样品至溶液呈透明，再用琼脂溶液悬浮极少量不溶物，制成样品溶液。分别以Sr^2 溶液和NaCl溶液作为测定镁、钾的释放剂和消电离剂。以原子吸收光谱法测定镁、锌，以原子发射光谱法测定钾。对样品处理方法、干扰、线性范围及检出限进行了考察。建立了快速测定蘑菇中钾、镁、锌的火焰原子光谱法。相对标准偏差小于2.8%，加标回收率为97.9%-101.6%。     

微波消解-火焰原子吸收光谱法测定饲料中铁铜锰锌

铁、铜、锰和锌是饲料中重要的营养元素，其含量的测定已有标准方法，该法虽有较高的灵敏度，但分析时间冗长，试样的灰化就需16h，很难满足批量样品测定的需要。本文采用微波技术消解饲料样品，用火焰原子吸收光谱法测定铁、铜、锰和锌的含量，方法快速、灵敏、准确、操作简便。试样前处理仅需0．5h，节省了分析时间，应用于样品的分析，结果满意。     

茶叶中微量营养元素的原子吸收光谱分析

茶叶中的微量元素与茶叶的营养和药理作用有密切关系^[1],与茶树生长的生化活动也有密切关系^[2,3]。对茶叶中的微量营养元素的分析有助于了解茶叶的品质,研究茶叶的营养药理作用,促进茶叶生产的发展。为此,我们研究提出了用火焰原子吸收光谱法测定茶叶中铜、锰、铁、锌,方法简便、准确。     

Separation and preconcentration of trace manganese from various samples with Amberlyst 36 column and determination by flame atomic absorption spectrometry

This work assesses the potential of a new adsorptive material, Amberlyst 36, for the separation and preconcentration of trace manganese(II) from various media. It is based on the sorption of manganese(II) ions onto a column filled with Amberlyst 36 cation exchange resin, followed by the elution with 5 mL of 3 mol/L nitric acid and determination by flame atomic absorption spectrometry (FAAS) without interference of the matrix. Different factors including pH of sample solution, sample volume, amount of resin, flow rate of sample solution, volume and concentration of eluent, and matrix effects for preconcentration were investigated. Good relative standard deviation (3%) and high recovery (>95%) at 100 μg/L and high enrichment factor (200) and low analytical detection limit (0.245 μg/L) were obtained. The adsorption equilibrium was described well by the Langmuir isotherm model with maximum adsorption capacity of 88 mg/g of manganese on the resin. The method was applied for the manganese determination by FAAS in tap water, commercial natural drinking water, commercial treated drinking water and commercial tea bag sample. The accuracy of the method is confirmed by analyzing the certified reference material (tea leaves GBW 07605). The results demonstrated good agreement with the certified values.     

On-line determination of manganese in solid seafood samples by flame atomic absorption spectrometry

Manganese is extracted on-line from solid seafood samples by a simple continuous ultrasound-assisted extraction system (CUES). This system is connected to an on-line manifold, which permits the flow-injection flame atomic absorption spectrometric determination of manganese. Optimisation of the continuous leaching procedure is performed by an experimental design. The proposed method allows the determination of manganese with a relative standard deviation of 0.9% for a sample containing 23.4 μg g⁻¹ manganese (dry mass). The detection limit is 0.4 μg g⁻¹ (dry mass) for 30 mg of sample and the sample throughput is ca. 60 samples per hour. Accurate results are obtained by measuring TORT-1 certified reference material. The procedure is finally applied to mussel, tuna, sardine and clams samples.     

Chemical analysis of manganese nodules: Part IV. Determination of Nickel after Anion-exchange Separation

A method is described for the a.a.s. determination of nickel in manganese nodules after its separation from interfering metals. After dissolution of the sample in a mixture of perchloric and hydrofluoric acids, manganese, iron, cobalt, copper and other elements are adsorbed on the strongly basic anion exchange resin Dowex 1 (chloride form) from 95% ethanol-5% 12 M hydrochloric acid. The nickel passes into the effluent in which it is determined by a.a.s. with an air-acetylene flame. The method was used successfully for the determination of nickel in numerous samples of nodules from the Pacific Ocean.     

Fast Multi‐residue Screening for 84 Pesticides in Tea by Gas Chromatography with Dual‐tower Auto‐sampler,Dual‐column and Dual Detectors

A fast multi‐residue screening method for determining pesticides in tea is described. Pesticides are extracted from tea with acetone and methylene chloride, then enriched and cleaned up with solid phase extraction (SPE) prior to gas chromatographic determination. The fast screening is achieved by a gas chromatograph system equipped with dual‐column, dual‐tower auto‐sampler and both electron capture detector (ECD) and flame photometric detector (FPD). Optimal conditions are investigated for the prospective pesticides including column selection, detection mode, the retention behaviors, quantitative calibration, as well as the recoveries and repeatability of pesticides from tea samples. Under the optimal conditions, with the FPD‐P detector accompanied CP‐SIL 13CB column, 48 pesticides can be separated well and detected within 38 min; and with a DB‐5 column, 35 ECD‐detectable pesticides can be separated and detected within 46 min. The recoveries of 84 pesticides in tea samples are 65–120% with 0.34–16% RSD for spiking 0.02–3.0 mg/kg standard species. Because of the thermal instability of most pesticides, direct cold extraction of pesticides from a tea sample is recommended. The proposed method provided a very fast and efficient procedure to screen 84 pesticides from a complicated tea sample matrix.     

Spectrophotometric determination of the pH scale in ethane-1,2-diol

A highly selective method is described for the determination of gallium at the ppm-level in manganese nodules and geological reference samples. After dissolution of the sample, gallium is adsorbed on Dowex 1 (chloride form) from hydrochloric acid solution containing titanium trichloride, which reduces iron(III) so that it is not adsorbed. After elution with dilute nitric acid and evaporation, gallium is determined by atomic-absorption spectrometry with an air-acetylene flame.     

Silberhalogenide als Spurenfänger für Chelatkomplexe

The power of detection of flame AAS for trace elements decreases considerably in presence of manganese. For the purity control of manganese and manganese compounds, therefore, it is necessary to separate the traces from the main component of the samples. For that purpose the traces were complexed by 1,10-phenanthroline and coprecipitated by silver iodide as trace collector. To receive a trace solution of 10 ml being free of manganese the filtered AgI was boiled with HNO₃. The enriched elements (Fe, Co, Ni, Cu, Zn, Cd, Pb, Bi and Tl) were determined by flame AAS. Using samples of 5 to 10 g of manganese or manganese compounds of different stages of oxidation the limits of detection of the various elements were found to be in a range between 0.01 and 1 ppm. By evaporation of the trace solution down to 1 ml and determination of the traces by the “injection method” of flame AAS limits of detection are obtained between 0.007 and 0.1 ppm.     

Flame atomic absorption spectrometric determination of trace amounts of manganese in alloys and biological samples after preconcentration with the ion pair of 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol and ammonium tetraphenylborate on microcrystalline naphthalene or by column method.

Manganese is quantitatively retained on 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP)-ammonium tetraphenylborate with microcrystalline naphthalene or by a column method in the pH range 7.5-10.5 from large volumes of aqueous solutions of various samples. After filtration, each solid mass consisting of the manganese complex and naphthalene was dissolved with 5 ml of dimethylformamide and the metal was determined by flame atomic absorption spectrometry. Manganese complex can alternatively be quantitatively adsorbed on ammonium tetraphenylborate-naphthalene adsorbent packed in a column and determined similarly. About 0.1 microgram of manganese can be concentrated in a column from 500 ml of aqueous sample, where its concentration is as low as 0.2 ppb. Eight replicate determinations of 1.0 ppm of manganese gave a mean absorbance of 0.224 with a relative standard deviation of 1.8%. The sensitivity for 1% absorption was 19 ppb. The interference of a large number of anions and cations has been studied and the optimized conditions developed were utilized for the trace determination of manganese in various standard samples.     

Optimization of a new resin, Amberlyst 36, as a solid-phase extractor and determination of copper(II) in drinking water and tea samples by flame atomic absorption spectrometry

A new simple and reliable method has been developed to separate and preconcentrate trace copper ion in drinking water and tea samples for subsequent measurement by flame atomic absorption spectrometry (FAAS). The copper ions are adsorbed quantitatively during passage of aqueous solutions through Amberlyst 36 cation exchange resin. After the separation and preconcentration stage, the analyte was eluted with a potassium cyanide solution and determined by FAAS. Different factors including pH of sample solution, sample volume, amount of resin, flow rate of aqueous solution, volume and concentration of eluent, and matrix effects for preconcentration were examined. The analytical figures of merit for the determination of copper are as follows: analytical detection limit (3 sigma), 0.26 microg/L; precision (RSD), 3.1% for 100 microg/L; enrichment factor, 200 (using 1000 mL of sample solution and 5 mL of eluent); time of analysis, 3.5 h (for obtaining enrichment factor of 200); capacity of resin, 125 mg/g. The method was applied for copper determination by FAAS in tap water, commercial natural spring water, commercial treated drinking water, and commercial tea bag sample. The accuracy of the method is confirmed by analyzing tea leaves (GBW 07605). The results demonstrated good agreement with the certified values.