热水解-离子选择电极法测定海相碳酸盐岩中的氟

采用热水解法对样品进行预处理,离子选择电极法简易快速测定海相碳酸盐岩中氟元素的含量。方法检出限为25.1μg/g,精密度(RSD,n=11)为5.28%,回收率为96.5%~107.8%,结果令人满意。     

碱熔-离子色谱法同时测定玻璃中的氟和硫

玻璃样品中加入氢氧化钠,在700℃马弗炉中加热熔融,热水浸提,所得溶液通过OnGuardⅡAg/H柱后上机测定,消除加入的氯和碱的干扰,再经IonPac AG14柱和AS14柱分离,采用小体积的定量环直接进样,离子色谱法测定氟离子和硫酸根的含量。氟离子和硫酸根的线性范围分别为0.1～2μg/mL和0.5～20μg/mL,方法检出限氟为2.0 mg/kg和硫为1.0 mg/kg,测定结果的相对标准偏差(RSD)小于5.0%。实际玻璃样品用离子色谱法和化学法测定,两种分析方法的结果无显著性差异。     

对磺基苯偶氮变色酸分光光度法测定岩石样品中的氟

采用对磺基苯偶氮变色酸分光光度法对岩石样品中氟的含量进行测定。确定的最佳测定条件为:测定波长570 nm,放置2 h后测定,盐酸介质浓度0.84 mol/L,显色剂用量5.0 mL。氟离子浓度在0~1.4 mg/L时符合比尔定律,方法检出限为0.06μg/g。以岩石标准物质代替氟标准溶液制作标准曲线,可有效降低杂质元素的干扰。对国家一级标准物质和日本玄武岩标准物质6次测定的相对标准偏差(RSD)为2.37%~6.32%。     

高温燃烧水解-离子色谱法测定植物样品中的氟

建立了高温燃烧水解-离子色谱测定植物样品中不同含量范围氟的分析方法,色谱条件为Dionex IonPacAS18分离柱(4 mm×250 mm),Dionex IonPac AG18保护柱(4 mm×50 mm),ASRS ULTRAⅡ自动再生微膜抑制器,电导检测器。采用纯水作为吸收介质,使样品溶液与标准溶液基体一致,过滤后可直接测定。样品溶液中常见的Cl-、NO3-、SO24-、PO43-、CO23-、HCO3-等阴离子不干扰F-的测定。为消除样品热解过程中产生的乙酸干扰,对氟含量较高(xx～xxxμg/g)的样品,采用20 mmol/L的NaOH淋洗液等度淋洗,进样体积为25μL;对氟含量较低的样品(0.x～xμg/g),进样体积为100μL。方法具有较宽的线性范围和较好的稳定性,检出限为0.5 mg/kg,适用于痕量分析;应用于灌木枝叶和茶叶等4个氟含量较高(xx～xxxμg/g)的植物标准物质的测定,相对标准偏差(RSD)<6%(n=6);应用于低氟的小麦粉和大米粉样品测定,加标回收率为90%～110%,可以满足不同氟含量植物样品中氟测定的需要,具有自动化程度高、操作简单、对环境友好等特点。     

用离子色谱法测定地质样品中的氟、氯、硫

地质样品中氟、氯、硫的测定是十分重要的,这是由于氟是矿化作用的可靠标志,而且氟、氯、硫也被认为是不同类型沉积矿物的指示元素。地质样品中氟的测定方法通常采用氟离子选择电极法(别婉琳等,1980),氯的测定一般采用碱熔-硫氰酸汞比色法或碱熔硝酸汞滴定法等。     

运城地区水氟回升原因及重病区水氟有效值的确定

本文介绍了山西省运城地区十年改水的基本情况，指出了改水井口氟加升的主要原因，探讨了有别于国家饮水标准的重病区水氟防治有效值的确定方法、并对今后的降氟改水工作提出了几点意见。     

The analysis of geological materials for fluorine,chlorine and sulphur using pyrohydrolysis and ion chromatography

A rapid, efficient and interference-free method of determining fluorine, chlorine and sulphur in geological materials is described. The proposed pyrohydrolysis-ion chromatographic method was optimised by investigating experimental conditions and the results were compared with established methods using in-house control samples. Accuracy was evaluated by analysis of 13 international reference samples and found to be excellent for all three elements. The limit of determination for a 100-mg sample is 20 μg g⁻¹ for the three elements and the precision averages about ±5% relative standard deviation at levels greater than 100 μg g⁻¹ up to percent amounts. Sample preparation is minimal, possibility of contamination negligible and cost per analysis low. The productivity rate is about 40 samples per day with one operator using two furnaces and the automated chromatograph.     

离子色谱法测定土壤中有效氟

利用离子交换-电导检测离子色谱法对土壤中有效氟进行测定。选用30 mmol/L氢氧化钾溶液作为淋洗液,流速1.20 mL/min,准确测定有效态(可提取态)氟含量。方法加标回收率为95%~108%,精密度好,检出限低,操作简单,对环境无污染,适合于土壤污染状况的调查。     

扩散-离子色谱法测定植物样中的氟

采用扩散法提取植物样中的氟,用离子色谱法检测氟的含量。经试验,样品加标回收率在94.7%～104.7%之间,样品质量分数为7.10μg/g时,RSD为1.41%。此法操作简单,准确度高,精密度好,是一种测量植物样中氟含量的有效方法。     

Results for Fluorine in Coals and Other Reference Materials

Results of fluorine determinations by a pyrohydrolysis-ion selective electrode method are reported for four reference coals, two fly ashes and eight rock samples. These values were obtained during a study of Australian coals which showed that the standard oxygen bomb combustion method generally used for coals gives low results. The results are compared with available literature data for these reference samples which were obtained by a variety of methods.     

RAPID NON-DESTRUCTIVE DETERMINATION OF FLUORINE IN SEVENTY-ONE GEOLOGICAL AND OTHER REFERENCE SAMPLES USING FAST-NEUTRON ACTIVATION ANALYSIS

The fluorine concentration in seventy-one reference samples of geological interest has been determined using fast-neutron activation analysis. The reaction involved [¹⁹F(n, α) ¹⁶N] uses accelerator-derived neutrons produced by bombarding a Be target with 3 MeV deuterons. The gamma radiation associated with the decay of ¹⁶N (t1/2 = 7.13 s) is counted and for the irradiation conditions used there are no serious interferences. The advantages of this technique over other schemes of fluorine determination are its simple procedure for sample preparation, speed, high sensitivity and non-destructiveness. A comparison of the data obtained with those in the literature is highly favourable.     

The distribution of fluorine among some coexisting minerals

Coexisting Ca-amphiboles, biotites, apatites, and sphenes were analysed for fluorine by a micro-probe. Fifty samples from four areas were examined. The distribution coefficient K _D(F) ^A-B for coexisting Ca-amphibole and biotite varies between 0.5 and 1.1 and is positively correlated with increasing metamorphic grade and with increasing contents of Ti in Ca-amphibole. Samples carrying hematite have normally a higher content of fluorine in the hydrous minerals due to an increasing activity of fluorine during the oxidation. It is shown that apatite mirrors a low activity of fluorine better than coexisting biotite, which in turn is a more sensitive indicator at higher F-activities. The distribution of fluorine between sphene and biotite is also discussed.     

The use of fluorine as a pathfinder for volcanic-hosted massive sulfide ore deposits

A multi-element geochemical study of the wall rocks of intermediate to felsic volcanic-hosted massive sulfide deposits was carried out to identify pathfinder elements which significantly enlarge the size of exploration targets. Drill core samples from the Crandon massive sulfide deposit in Wisconsin, and outcrop samples from the United Verde and Iron King deposits in Arizona, and from the Captains Flat, Mt. Costigan, and Wiseman Creek deposits in New South Wales, Australia were analyzed. Because anomalously high fluorine values have been described in several volcanic-hosted ore systems, fluorine was included in the study.All of the above deposits have patterns of fluorine enrichment around ore. Drill core samples from two noneconomic prospects within ten miles of the Crandon deposit contain background to only weakly anomalous fluorine values.At the large Crandon deposit (> 50 million tons of zinc, copper ore), fluorine enrichment extends approximately 320 m into the footwall rocks and at least 220 m into the hanging wall rocks. At the large United Verde deposit (> 50 million tons of copper, zinc ore), fluorine enrichment is recognizable in the footwall rocks at least 650 m from the ore. At the smaller Iron King deposit (five million tons production of zinc, lead, copper ore), fluorine enrichment extends for a distance of approximately 60 m into the footwall rocks. At the small deposits in New South Wales (< five million tons production of zinc, lead, copper ore), fluorine enrichment is easily recognizable, but with the samples collected, the limits of the anomalous patterns cannot be defined.Fluorine occurs in some hydrothermal systems unassociated with mineralization and is therefore not a specific signature of ore-forming processes. From the work completed, many massive sulfide deposits in volcanic rocks occur in hydrothermal systems which contain fluorine. On the basis of the data presented, if anomalously high fluorine values do exist in an exploration search area, the chances of finding a massive sulfide ore deposit are improved.Genetic models for volcanic-hosted massive sulfide ore deposits have concentrated on rock textures, alteration mineralogy, and geochemistry of the ore metals. From the data presented, fluorine should be considered as a component of massive sulfide systems in intermediate to felsic volcanic rocks, and should be considered as a possible complexing agent for the ore metals.     

离子选择电极法测定土壤中水溶性氟提取液温度的控制方式

采用超声提取法对样品进行预处理,利用离子选择电极法测定土壤中的水溶性氟,超声空化热效应会造成提取液温度升高,检测结果不稳定,不能如实反映土壤中水溶性氟含量,对土壤环境中氟的监测造成困扰.因此,选择有效的控制提取液温度方式至关重要.本文通过记录直接超声、加冰袋、加冰水、冷却循环水四种温度控制方式提取液温度变化确定出最佳温...     

Fluorine in drinking water and urine in the urban and rural areas of northwestern China——Its determination by a fluoride ion selective electrode

In this study, the author determined fluorine in drinking water and urine of residents who are divided into four age groups (5, 12, 35-44, 65-74 aged), living in Huangling City, Shaanxi Province and at 6 villages of Qin'an County, Gansu Province, P.R.China. Some residents are living in fluorine exposure areas. A total of 929 residents (463 females and 466 males) involved in the study were selected from 7 tap water systems. Drinking water samples were collected from each area and analyzed using the fluoride ...     

Fluorine in tourmalines

The determination of the fluorine content of courmalines yielded 0.28% as an average value for schorlites and dravites and 0.97% for elbaites. The plot of the fluorine contents against the lithium contents shows that the distribution of projection points for pink or green elbaites differs from that for lithian indigolites. Tourmalines are poorer in fluorine than lightcoloured micas at the same stage of pegmatite evolution. Individual regions with pegmatite occurrences can be characterized as rich or poor in fluorine according to the fluorine contents in the tourmalines and micas contained in the pegmatites.     

氟离子选择电极测定半微量矿物中的氟

单矿物半微量分析中氟的测定通常采用氟试剂比色法,此法灵敏,但费时而繁琐。离子选择电极法是新的电化学分析方法,目前氟电极测定氟已用于常规分析中,但一般岩矿分析,氟电极实测线性范围为1×10^-1M-1×10^-5M²。     

Fluorine in Some CII Biological Reference Samples and Fluorine Losses During Ashing

Twelve different biostandards from the Inter-Institute Comittee for studying analytical techniques for leaves (CII) contain fluorine in the range of 6 to 37 ppm. It is known that biological samples from areas affected by fluorine emission may contain up to 1000 ppm of F or more. After keeping the reference samples for two hours at 500°C, weight losses between 67 and 78% are observed; the fluorine losses are between 40 and 85%. If conventional analytical techniques are used, an ashing procedure is necessary before the samples could be fused. By using pyrohydrolytical technique the ashing step is omitted and, hence, any loss of fluorine can be avoided.     

FLUORINE ABUNDANCES OF TWENTY NINE GEOLOGICAL AND OTHER REFERENCE SAMPLES USING FAST-NEUTRON ACTIVATION ANALYSIS

The fluorine content in twenty-nine reference samples of geological interest has been determined using a well tried and tested method which has been previously reported. The analytical method uses fast neutron activation involving the reaction ¹⁹F(n,a)¹⁶N and gamma spectrometry. Interferences have been found to be negligible for the experimental conditions used. The method involves minimal sample preparation, is rapid and can easily measure concentrations down to 5 parts per million in a 5 g sample.     

高氟湖库底泥中氟的存在形态分析——以洋沙泡水库为例

论述了底泥中氟的存在形态及其浸提方法。通过洋沙泡水库底泥氟各种形态的分析实验,发现底泥氟形态的含量分布为残余态水溶态>有机态>铁锰结合态>可交换态;底泥各形态氟含量呈对数分布;水溶性氟质量分数为26.77~112.39 mg/kg,占总氟的2.699%~19.114%。底泥全氟含量、氟的来源、气候因素的影响、区域理化环境以及湖泊曾数度干涸是造成水溶性氟含量高的主要原因。