Responses of human neutrophils to sulfite

Exposure to sulfur dioxide or sulfite aerosols induce inflammatory reactions in the respiratory tract characterized by an influx of neutrophils into the airways. To determine direct intracellular effects of sulfite on human neutrophils, these cells were evaluated ultrastructurally by electron microscopy and analyzed for their extracellular and intracellular respiratory burst activity after incubation with sulfite (0.01-10 mM) in vitro. The respiratory burst was quantitated by measuring both the extracellular release of superoxide anions (O2-) by superoxide dismutase-inhibitable lucigenin-dependent chemiluminescence (CL) and the intracellular generation of hydrogen peroxide (H2O2) by flow cytometry using the reagent dichlorofluorescein diacetate. The addition of sulfite in concentrations of 0.01-1 mM resulted in sixfold increases in CL of resting neutrophils. Neutrophils stimulated with zymosan, phorbol myristate acetate (PMA), or N-formyl-methionine-leucine-phenylalanine further increased CL when sulfite was added. Higher sulfite concentrations (2-10 mM) decreased CL of resting, zymosan-stimulated, and PMA-stimulated cells. When sulfate was added, no changes in CL of resting and zymosan-stimulated neutrophils were seen, indicating that the effect is specific for sulfite. The intracellular generation of H2O2 in resting and PMA-stimulated neutrophils incubated with sulfite (0.1-2 mM) was increased twofold. These findings suggest that sulfite in low concentrations stimulates neutrophils by activating the respiratory burst to produce O2- and H2O2. Ultrastructural studies confirm the stimulating effect of sulfite on neutrophils with sulfite-treated cells exhibiting increased ruffled surface membranes, degranulation changes, and vesiculation similar to those seen in PMA-stimulated cells.     

Use and removal of sulfite by conversion to sulfate in the preservation of salt-free cucumbers

Cucumbers (Cucumis sativus) were microbiologically stable in cover liquid containing 300 ppm of added sodium metabisulfite (calculated as SO2), 20 mM calcium chloride, and HCl to give an equilibrated pH of 3.5. The sulfur(IV) oxoanions could be easily removed to nondetectable levels (< 3 ppm) by addition of an equimolar amount of hydrogen peroxide, which rapidly converted S(IV) primarily to sulfate ions. When sulfur(IV) oxoanions were removed from stored fresh cucumbers, 85% of the added metabisulfite could be accounted for by formation of sulfate ions. If cucumbers were heated before addition and removal of sulfur(IV) oxoanions, 96% of that added was converted to sulfate by hydrogen peroxide. Preservation of cucumbers in this way does not require fermentation, so addition of salt is not needed to select for lactic acid bacteria.     

低品位氧化锰矿酸浸制备硫酸锰

研究一步法还原浸出低品位氧化锰矿制备硫酸锰工艺。使用亚硫酸盐作为还原剂,采用黄铁矾法除铁,硫化盐法去除重金属离子,最终制备出适用于电解的硫酸锰溶液。结果表明:矿样10g,硫酸用量6mL,亚硫酸钠用量6g,90℃浸出100min,可以获得的96.42%锰浸出率;控制中和调浆终点pH=2.5,铁浸出率0.02%;控制除杂终点pH=4.5时,滤液达到合格电解液的标准。     

Regulation of leukotriene and platelet-activating factor synthesis in human alveolar macrophages

It has been suggested that phospholipase A2 (PLA2) contributes to the regulation of leukotriene (LT) and platelet-activating factor (PAF) synthesis by controlling the release of their precursors, arachidonic acid (AA) and lysophosphatidylcholine (lysoPC), from membrane phospholipids. In rat alveolar macrophages (AMs), PLA2 appears to have a major role in LT synthesis but a more limited role in PAF synthesis. The present study was designed to define the role of PLA2 in LT and PAF synthesis in human AMs and determine whether differences exist between AMs obtained from normal subjects and those from patients with asthma. In the normal subjects, the calcium ionophore A23187 (Cal) increased AM PAF synthesis (percent incorporation of tritiated acetate) by 135% (p < 0.01) and LTB4 synthesis 88-fold (p < 0.001). Phorbol myristate acetate (PMA) had little effect alone, but it had a synergistic effect with Cal, increasing PAF synthesis by 466% and LTB4 synthesis to 229-fold above the control values (p < 0.001 for both). Ro 25-4331, a combined cytosolic (c) and secretory (s) PLA2 inhibitor, had little effect on the Cal-stimulated PAF synthesis, but it completely blocked the effect of PMA. It also blocked the Cal- and Cal+PMA-stimulated LTB4 synthesis. AACOCF3, a cPLA2 inhibitor, had no effect on either Cal or Cal+PMA-stimulated PAF synthesis. It reduced LTB4 synthesis, but it did so less effectively than Ro 25-4331. CoA-independent transacylase (CoAI-TA) activity in the AMs increased after stimulation and exposure to Ro 25-4331. SK&F 45905, a CoAI-TA inhibitor, reduced stimulated PAF synthesis by 30% to 40%. Patients with asthma had similar results except that cPLA2 had a greater role in stimulated LTB4 synthesis. These data indicate that PLA2 plays a direct role in human AM LT synthesis; both the cytosolic and secretory forms contribute to LT synthesis; PLA2 appears to have a more limited role in PAF synthesis, although it mediates the synergistic effect of PMA, probably via sPLA2; and CoAI-TA contributes to PAF synthesis during PLA2 inhibition. With the exception of the greater role for cPLA2 in stimulated LTB4 synthesis in the patients with asthma, the contributions of PLA2 and CoAI-TA to AM LT and PAF synthesis appear to be similar in normal subjects and patients with asthma.     

Cloning and expression of a group IV cytosolic Ca2+-dependent phospholipase A2 from rat pancreatic islets. Comparison of the expressed activity with that of an islet group VI cytosolic Ca2+-independent phospholipase A2

Stimulation of pancreatic islets with glucose induces phospholipid hydrolysis and accumulation of nonesterified arachidonic acid, which may play signaling or effector roles in insulin secretion. Of enzymes that catalyze phospholipid hydrolysis, islet beta-cells express low molecular weight secretory phospholipases A2 (PLA2) and a Group VI, Ca2+-independent PLA2 (iPLA2). Previous studies indicate that islets also express a protein recognized by antibodies against a Group IV, cytosolic, Ca2+-dependent PLA2 (cPLA2). To further examine the possible expression of cPLA2 by islets, we screened a rat islet cDNA library with a probe that recognizes cPLA2 sequence, and isolated a full-length cPLA2 cDNA. The rat islet cPLA2-deduced amino acid sequence is 96% identical to those of human and mouse cPLA2. Transfection of COS-7 cells with cPLA2 cDNA in an expression vector induced expression of Ca2+-dependent PLA2 activity and of a protein recognized by anti-cPLA2 antibody. Comparison of recombinant islet cPLA2 and iPLA2 activities expressed in transfected COS-7 cells indicated that iPLA2 but not cPLA2 is stimulated by ATP. Both activities are similarly sensitive to inhibition by arachidonyltrifluoromethyl ketone, but iPLA2 is more effectively inhibited by a haloenol lactone suicide substrate than cPLA2. RT-PCR experiments with RNA from purified islet beta-cells and from an alpha-cell-enriched population prepared by fluorescence-activated cell-sorting indicated that cPLA2 mRNA is more abundant in the beta-cell population. Immunoblotting analyses indicate that islets express cPLA2-immunoreactive protein, and that interleukin-1 does not affect its expression. The cPLA2 is thus one of at least three classes of PLA2 enzymes with distinct properties expressed in beta-cells.     

Homogeneous catalyst for DNA hydrolysis (4). Efficient DNA hydrolysis by lanthanide--saccharide complexes

Homogeneous and neutral solutions are prepared by mixing Ce(NH4)2(NO3)6 with either isomaltose, melibiose, gentiobiose, palatinose, mannitol, sorbitol, galactitol, or glucamine in pH 7 hepes buffer ([Ce(IV)]0/[monomeric residue of saccharide]0 = 1). In contrast, amylose, cyclodextrins, maltose, glucose, and fructose provide only heterogeneous mixtures. The homogeneous solution of 1:1 Ce(IV)/glucamine system is active for DNA hydrolysis: the pseudo-first-order rate constant for the hydrolysis of thymidylyl(3'-->5')thymidine at pH 7.0 and 50 degrees C is 0.010 h-1, when [Ce(IV)]0 = [glucamine]0 = 10 mmol dm-3. The DNA-hydrolyzing activity decreases in the following order: glucamine > isomaltose, melibiose, gentiobiose > palatinose, mannitol, sorbitol, galactitol.     

Comparative aspects of utilization of sulfonate and other sulfur sources by Escherichia coli K12

Selected biochemical features of sulfonate assimilation in Escherichia coli K-12 were studied in detail. Competition between sulfonate-sulfur and sulfur sources with different oxidation states, such as cysteine, sulfite and sulfate, was examined. The ability of the enzyme sulfite reductase to attack the C-S linkage of sulfonates was directly examined. Intact cells formed sulfite from sulfonate-sulfur. In cysteine-grown cells, when cysteine was present with either cysteate or sulfate, assimilation of both of the more oxidized sulfur sources was substantially inhibited. In contrast, none of three sulfonates had a competitive effect on sulfate assimilation. In studies of competition between different sulfonates, the presence of taurine resulted in a decrease in cysteate uptake by one-half, while in the presence of isethionate, cysteate uptake was almost completely inhibited. In sulfite-grown cells, sulfonates had no competitive effect on sulfite utilization. An E. coli mutant lacking sulfite reductase and unable to utilize isethionate as the sole source of sulfur formed significant amounts of sulfite from isethionate. In cell extracts, sulfite reductase itself did not utilize sulfonate-sulfur as an electron acceptor. These findings indicate that sulfonate utilization may share some intermediates (e.g., sulfite) and regulatory features (repression by cysteine) of the assimilatory sulfate reductive pathway, but sulfonates do not exert regulatory effects on sulfate utilization. Other results suggest that unrecognized aspects of sulfonate metabolism, such as specific transport mechanisms for sulfonates and different regulatory features, may exist.     

Triplex formation at physiological pH by oligonucleotides incorporating 5-Me-dC-(N4-spermine)

Oligonucleotide (ODN) directed triplex formation has therapeutic importance and depends on Hoogsteen hydrogen bonds between a duplex DNA and a third strand. While T*A:T triplets are formed at neutral pH, C+*G:C are favoured at acidic pH. Herein it is shown that 18-mer ODN containing spermine conjugated to 5-Me-dC at N4 (1-5), form triplexes with complementary 24-mer duplex 8:9 at neutral pH (7.3, 100 mM NaCl). Under such conditions, control ODN's carrying dC (6) or 5-Me-dC (7) did not show any triple helix formation. Remarkably, the triplexes from spermine-conjugates (1-5) have foremost stability at neutral pH (7.1), unlike the behavior of normal ODN's where optimal stability is at acidic pH (5.5). These results have importance in designing oligonucleotides for antigene applications.     

碘量-重量法测定脱硫灰还原产物中硫化钙和亚硫酸钙

准确测定硫化钙和亚硫酸钙的含量,对于脱硫灰还原工艺的参数选择和转化进程的研究具有重要意义。用过量碘标准滴定溶液将样品中的硫化钙和亚硫酸钙氧化,磷酸(1+4)溶液溶解样品并调节pH值,硫代硫酸钠标准滴定溶液返滴定得到硫化钙和亚硫酸钙消耗的碘标准滴定溶液的量,从而得到硫化钙和亚硫酸钙的总含量;硫化钙与碘反应生成硫单质,用热氢氧化钾溶液洗脱生成的硫单质的质量得到样品中硫化钙的含量,两者之差即为亚硫酸钙的含量,从而建立了脱硫灰还原产物中硫化钙和亚硫酸钙的测定方法。将实验方法应用于不同工艺流程得到的脱硫灰还原产物测定,7次平行测定硫化钙和亚硫酸钙结果的相对标准偏差(RSD,n=7)为0.54%~1.8%。按照实验方法,对3种配制的脱硫灰还原产物中硫化钙和亚硫酸钙进行测定,测定值均和理论值相符。     

铬酸钡分光光度法测定铁矿石中硫

铁矿石中硫含量影响到成品钢质量,因此硫含量的快捷准确测定极其重要。在780 ℃下碳酸钠和氧化锌混合熔剂半熔铁矿石样品,将其中的硫转换为硫酸盐后,用沸水溶解硫酸盐并过滤,同时用20 g/L热碳酸钠溶液多次洗涤沉淀,用铬酸钡分光光度法测量滤液中硫酸盐含量,从而建立了分光光度法测定铁矿石中硫含量的方法。条件优化试验表明:需用热的碳酸钠溶液洗涤沉淀与烧杯才能保证铁矿石中的SO₄^2-全部留存在液体中;添加铬酸钡溶液后煮沸时间应大于2 min才能保证铬酸钡全部转化为硫酸钡;添加铬酸钡煮沸后的溶液需用氨水(1+1)调至pH值大于10,Cr(VI)才能完全以CrO₄^2-的形式存在,从而不影响测定结果。铁矿石中硫质量分数为0.014 %~0.30 %时与吸光度呈线性关系,线性相关系数为0.999 3。方法检出限为0.003 7 %,定量限为0.026 0 %,表观摩尔吸光系数为5.75×10² L·mol^-1·cm^-1。为了验证硫元素不同存在形态的测定偏差,按照实验方法对单质硫、亚硫酸钠、硫酸钠、硫化亚铁以及铁矿石的标准物质分别进行测定,测定结果的相对误差为-3.63%~3.77%。选择3个实验组,按照实验方法对铁矿石中硫含量进行测定,每个实验组分别按照实验方法平行测定7次,结果的相对标准偏差(RSD,n=3)为3.7%,测定结果与国标法GB/T 6730.16—2016中硫酸钡重量法相吻合。     

碘量-重量法测定脱硫灰还原产物中硫化钙和亚硫酸钙

准确测定硫化钙和亚硫酸钙的含量,对于脱硫灰还原工艺的参数选择和转化进程的研究具有重要意义。用过量碘标准滴定溶液将样品中的硫化钙和亚硫酸钙氧化,磷酸(1+4)溶液溶解样品并调节pH值,硫代硫酸钠标准滴定溶液返滴定得到硫化钙和亚硫酸钙消耗的碘标准滴定溶液的量,从而得到硫化钙和亚硫酸钙的总含量;硫化钙与碘反应生成硫单质,用热氢氧化钾溶液洗脱生成的硫单质的质量得到样品中硫化钙的含量,两者之差即为亚硫酸钙的含量,从而建立了脱硫灰还原产物中硫化钙和亚硫酸钙的测定方法。将实验方法应用于不同工艺流程得到的脱硫灰还原产物测定,7次平行测定硫化钙和亚硫酸钙结果的相对标准偏差(RSD,n=7)为0.54%~1.8%。按照实验方法,对3种配制的脱硫灰还原产物中硫化钙和亚硫酸钙进行测定,测定值均和理论值相符。     

Solvent extraction characteristics of thiosubstituted organophosphinic acid extractants

Organophosphorus reagents are well known in solvent extraction. Commercial operations for the separation of cobalt from nickel have been successfully carried out using organophosphoric, -phosphonic, and -phosphinic acid extractants. Two new reagents in this class are the mono and dithio analogs of the commercial dialkylphosphinic acid, Cyanex 272. The replacement of oxygen by sulfur in these reagents enables extraction to be carried out at much lower pH.Characterization of Cyanex 272, Cyanex 302 (bis-(2,4,4-trimethylpentyl)-thiophosphinic acid), and Cyanex 301 (bis-(2,4,4-trimethylpentyl)-dithiophosphinic acid) has been undertaken. A comparison of the solvent extraction behavior of metallurgically important first-row transition metal ions from acidic sulfate solution by these reagents is reported. Distribution coefficients shift to lower pH with increasing sulfur substitution and decreasing pK_a of the extractant, the greatest effect being observed for nickel. Stoichiometry of the extraction reactions, and the nature of the metal complexes formed have been determined using slope analysis techniques and spectroscopic measurements.     

Isolation and structure elucidation of an intermediate in the photodegradation of ciprofloxacin

Ciprofloxacin decomposes photochemically in aqueous solutions at acidic pH forming two major degradation products. One of the products, isolated from irradiated solutions by flash chromatography, was 7-[(2-aminoethyl)amino]-1-cyclopropyl-6-fluoro-1, 4-dihydro-4-oxo-3-quinoline carboxylic acid. The compound was an intermediate in the photochemical process, which degraded after longer exposure with a high-pressure mercury lamp to an aromatic amino-compound, 7-amino-1-cyclopropyl-6-fluoro-1, 4-dihydro-4-oxo-3-quinoline carboxylic acid. The structure of the intermediate was elucidated on the basis of information from ultraviolet, mass and nuclear magnetic resonance spectra.     

硫酸钡重量法测定硫磺包芯线中硫

试样以过氧化钠-无水碳酸钠熔融,以蒸馏水浸取,将氢氧化物及磷酸盐等沉淀过滤除去,滤液以盐酸中和变为微酸性,加入氯化钡溶液使硫酸根定量生成硫酸钡沉淀,将沉淀过滤、灰化、灼烧、称量,计算硫的质量分数,从而实现了硫酸钡重量法对硫磺包芯线中硫含量的测定。研究表明:稀释比为40∶1,700 ℃熔融15 min,硫转化完全。沉淀条件表明:在0.5%～1%盐酸(体积分数)及微沸搅拌状态下缓缓加入氯化钡溶液,75～85 ℃温度下陈化1 h即可得到稳定准确的结果。方法用于实际样品分析,结果同GB/T 2449—2006(工业硫磺 差减法)测定值一致,相对标准偏差(RSD,n=6)小于0.20%。实验方法具有相对节约时间、实验室配置条件要求较低及成本较低的特点,更适用于硫磺包芯线中硫含量的常规检测。     

Measuring memory for source: some theoretical assumptions and technical limitations

In a search for pathogenetic mechanisms underlying retention hyperkeratosis, we examined the pH gradient over the stratum corneum in 13 male patients suffering from either x-linked recessive (XRI) or autosomal dominant ichthyosis vulgaris. For recording pH values, a flat glass electrode was repeatedly applied to the skin during tape stripping of mildly involved forearm skin. Before stripping, surface pH was higher in ichthyosis vulgaris (5.3 +/- 0.7; n = 7) than in XRI (4.6 +/- 0.4; n = 6; p < 0.05) and healthy control men (4.5 +/- 0.2; n = 7; p < 0.01). Removal of stratum corneum, which required 100-240 strippings in ichthyotic skin and 80-120 strippings in healthy control skin, disclosed markedly different pH variations in the two types of ichthyosis. The major abnormality in ichthyosis vulgaris skin was that a neutral pH was attained already halfway through the horny layer, possibly reflecting a congenital lack of acidic breakdown products from keratohyaline. By contrast, stripping of XRI skin revealed a shallow pH gradient that plateaued at 6.2-6.6, instead of about 7 as in normal and ichthyosis vulgaris skin. A likely explanation is the XRI-associated accumulation of cholesterol sulfate in lower stratum corneum. Our results suggest that the "acid mantle" of normal skin, which penetrates deep into the stratum corneum, is the combined result of cornification-associated organic acids and back-diffusion of acid material from the surface. Because corneocyte desquamation involves many pH-dependent enzymes, abnormalities in the transcorneal pH gradient might play a role in the pathogenesis of ichthyosis.     

Characterization of alpha-ketoglutarate-dependent taurine dioxygenase from Escherichia coli

The Escherichia coli tauD gene is required for the utilization of taurine (2-aminoethanesulfonic acid) as a sulfur source and is expressed only under conditions of sulfate starvation. The sequence relatedness of the TauD protein to the alpha-ketoglutarate-dependent 2,4-dichlorophenoxyacetate dioxygenase of Alcaligenes eutrophus suggested that TauD is an alpha-ketoglutarate-dependent dioxygenase catalyzing the oxygenolytic release of sulfite from taurine (van der Ploeg, J. R., Weiss, M. A., Saller, E., Nashimoto, H., Saito, N., Kertesz, M. A., and Leisinger, T. (1996) J. Bacteriol. 178, 5438-5446). TauD was overexpressed in E. coli to approximately 70% of the total soluble protein and purified to apparent homogeneity by a simple two-step procedure. The apparent Mr of 81,000 of the native protein and the subunit Mr of 37,400 were consistent with a homodimeric structure. The pure enzyme converted taurine to sulfite and aminoacetaldehyde, which was identified by high pressure liquid chromatography after enzymatic conversion to ethanolamine. The reaction also consumed equimolar amounts of oxygen and alpha-ketoglutarate; ferrous iron was absolutely required for activity; and ascorbate stimulated the reaction. The properties and amino acid sequence of this enzyme thus define it as a new member of the alpha-ketoglutarate-dependent dioxygenase family. The pure enzyme showed maximal activity at pH 6.9 and retained activity on storage at -20 degrees C for several weeks. Taurine (Km = 55 microM) was the preferred substrate, but pentanesulfonic acid, 3-(N-morpholino)propanesulfonic acid, and 1,3-dioxo-2-isoindolineethanesulfonic acid were also desulfonated at significant rates. Among the cosubstrates tested, only alpha-ketoglutarate (Km = 11 microM) supported significant dioxygenase activity.     

Left ventricular perimysial collagen fibers uncoil rather than stretch during diastolic filling

Workers in the pulp and paper industry are exposed to different substances, such as hydrogen sulfide and other reduced sulfur compounds, chlorine, chlorine dioxide, sulfur dioxide, terpenes, and paper dust. The exposure level depends on the process, i.e., sulfite, sulfate, groundwood, bleachery, or paper production. Hitherto, exposures have been poorly described and more studies are certainly needed. Workers with repeated exposure peaks to chlorine, e.g., bleachery workers, seem to have an impaired lung function and an increased prevalence of respiratory symptoms. Exposure to high levels of paper dust, (> 5 mg/m3) causes impaired lung function. Therefore, exposure to respiratory irritants is an important, and probably overlooked, occupational risk among certain groups of pulp and paper workers. Some studies indicate that sulfate workers with high exposure to reduced sulfur compounds have an increased mortality due to ischemic heart disease. However, before any definite conclusions can be drawn, the impact of important confounders, such as shift-work and smoking habits have to be further evaluated.     

Structure elucidation of a photodegradation product of ciprofloxacin

In the photochemical degradation of ciprofloxacin, 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(piperazinyl)-3-quinolone carboxylic acid, two major decomposition products are formed in acidic solution. The main degradation product, after both artificial and daylight exposure, was 7-amino-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-3-quinolone carboxylic acid. This product was also the dominating compound after more than 5 h irradiation with a high-pressure mercury lamp in aqueous solutions at pH < or = 2 when the solvent additionally contained water-miscible organic solvent. The structure of the isolated compound was elucidated on the basis of the chemical behaviour in thin-layer and high-performance liquid chromatography, and of information from infrared, ultraviolet, mass and nuclear magnetic resonance spectra.     

A glutamate-dependent acid resistance gene in Escherichia coli

Stationary-phase cultures of Escherichia coli can survive several hours or exposure to extreme acid (pH 2 to 3), a level well below the pH range for growth (pH 4.5 to 9). To identify the genes needed for survival in extreme acid, a microliter screening procedure was devised. Colonies from a Tn10 transposon pool in E. coli MC4100 were inoculated into buffered Luria broth, pH 7.0, in microtiter wells, grown overnight, and then diluted in Luria broth, pH 2.5, at 37 degrees C for 2 h. From 3,000 isolates screened, 3 Tet(r) strains were identified as extremely acid sensitive (<0.1% survival at pH 2.5 for 2 h). Flanking sequences of the Tn10 inserts were amplified by inverse PCR. The sequences encoded a hydrophobic partial peptide of 88 residues. A random-primer-generated probe hybridized to Kohara clones 279 and 280 at 32 min (33.7 min on the revised genomic map EcoMap7) near gadB (encoding glutamate decarboxylase). The gene was designated xasA for extreme acid sensitive. xasA::Tn10 strains grown at pH 7 to 8 showed 100-fold-less survival in acid than the parent strain. Growth in mild acid (pH 5 to 6) restored acid resistance; anaerobiosis was not required, as it is for acid resistance in rpoS strains. xasA::Tn10 eliminated enhancement of acid resistance by glutamic acid. xasA was found to be a homolog of gadC recently sequenced in Shigella flexneri, in which it appears to encode a permease for the decarboxylated product of GadB. These results suggest that GadC (XasA) participates in a glutamate decarboxylase alkalinization cycle to protect E. coli from cytoplasmic acidification. The role of the glutamate cycle is particularly important for cultures grown at neutral pH before exposure to extreme acid.     

硫掺杂偏钛酸粉体的制备

以硫酸钛为原料,采用水解法制备了硫掺杂偏钛酸粉体,采用场发射扫描电镜(FESEM)、激光粒度分析等技术对偏钛酸粉体的形貌及粒度进行了分析.系统研究了硫酸钛溶液浓度、水解温度、pH值对水解率、偏钛酸粉体粒径的影响,研究结果表明:硫酸钛溶液浓度、pH值及水解温度对偏钛酸颗粒粒径及原料水解率具有显著影响.最佳工艺条件为:硫酸钛溶液的质量浓度为65 g/L、水解温度60℃、pH值为7.