轻质油品痕量硫测定

介绍了一种测定轻质油品中测定痕量硫的仪器分析方法。使用ANTEK9000元素分析仪,根据紫外荧光法,微量注射器手动进样的方式测量石脑油馏分的痕量硫。结果表明,该方法检测限低,测定结果的相对标准偏差不大于5%,相对误差在±10%以内,具有操作简捷、准确度高、重复性好以及高选择性等优点,适用于痕量硫的测定。     

Determination of sulfur contents of vegetable and marine oils by ion chromatography and indirect ultraviolet photometry of their combustion products

A simple method for the determination of total sulfur content in vegetable and marine oils is described. The method involves combustion of the oil sample in an oxygen bomb to convert all forms of sulfur to sulfate ions with subsequent determination of the sulfate by ion chromatography and indirect ultraviolet detection. The ultraviolet system described is more sensitive than conductivity detection and enables the method to be applied more widely. Application of the method to a variety of vegetable and marine oils showed the general occurrence of sulfur in fats and oils, albeit often at a low level. Among the samples examined, crude Canola oil had the highest sulfur content (25.0 mg/kg) followed by the marine oils (5.8-15.2 mg/kg) and the non-Cruciferae vegetable oils (2.0-6.1 mg/kg). To whom correspondence should be addressed.     

微库仑法测定芳烃溶剂中硫含量的方法优化

从转化率和温度等方面对微库仑滴定技术测定芳烃溶剂中的硫含量的方法进行了优化.结果表明,采用优化的微库仑滴定法可以在芳烃溶剂中准确的测定小于l ng/μL样品的硫含量,该方法操作具有简单、快捷、准确的特点,可以很好的应用于芳烃溶剂中硫含量的测定.     

流动注射-分光光度法测定磷酸中三氧化硫质量分数

湿法磷酸生产中急需一种快速、准确的三氧化硫含量在线分析方法。采用流动注射将磷酸溶液连续注样,间断注入沉淀剂和EDTA清洗剂,分光光度法检测湿法磷酸中三氧化硫含量。结果表明:三氧化硫质量浓度测定的线性范围为40~160 mg/L,测定频率为27次/h,RSD<1.0%。本方法能够快速、准确地测定磷酸中三氧化硫含量,同时实现湿法磷酸生产或净化过程中三氧化硫浓度的在线监测。     

硅烷偶联剂总硫含量与平均硫链长度的测试

研究固体和液体偶联剂Si69总硫含量与平均硫链长度的测试方法。采用元素分析仪,以管式炉燃烧-红外吸收法测试偶联剂Si69的总硫含量;用质量分数为0.04%的四丁基溴化铵/乙醇/甲醇溶液(体积比为18/45/137)作为流动相,C₁₈柱分离,等度洗脱的方式,采用高效液相色谱仪测试偶联剂Si69的平均硫链长度。结果显示:固体偶联剂Si69试样的总硫含量为11.512%,平均硫链长度为3.59;液体偶联剂Si69试样的总硫含量为21.924%,平均硫链长度为3.60;固体偶联剂Si69总硫含量的测试精密度比液体偶联剂Si69高。     

高效液相色谱法测定40%硫磺·三唑酮·福美双可湿性粉剂

采用正相高效液相色谱法同时测定硫磺、三唑酮、福美双。该方法具有样品准备简单 ,共存组分互不干扰测定 ,分析速度快等优点 ,可以用于硫磺·三唑酮·福美双可湿性粉剂中有效成分的快速测定     

NEW APPLICATIONS OF CHEMILUMINESCENCE FOR SELECTIVE GAS ANALYSIS

Chemiluminescence (CL) is a powerful analytical tool for trace gas measurements. In this mini-review, we present reactions and spectra of ozone-induced CL for various compounds and techniques for detecting such CL. Next discussed are CL applications where real gas samples were successfully measured. Chemiluminescence monitoring has been used as universal nitrogen and sulfur detectors for gas chromatography and capillary electrophoresis. Chemiluminescence detection can be used as the basis of compact, affordable, and sensitive analyzers for real-sample analysis. Isoprene and sulfur compounds in breath and atmospheric samples have been successfully measured by coupling with a small collection system. Short-term (5 min) sorbent collection enhances the CL signal and considerably reduces interference. For sulfur gas analysis, methyl mercaptan and dimethyl sulfide can be separated on the same column that is used for collection. Waterborne arsenic is measured by automated arsine generation and CL reaction of arsine and ozone. In addition to gas-phase CL, more recent efforts towards the determination of gases by CL generated at solid/gas and liquid/gas interfaces are also discussed.     

NEW APPLICATIONS OF CHEMILUMINESCENCE FOR SELECTIVE GAS ANALYSIS

Chemiluminescence (CL) is a powerful analytical tool for trace gas measurements. In this mini-review, we present reactions and spectra of ozone-induced CL for various compounds and techniques for detecting such CL. Next discussed are CL applications where real gas samples were successfully measured. Chemiluminescence monitoring has been used as universal nitrogen and sulfur detectors for gas chromatography and capillary electrophoresis. Chemiluminescence detection can be used as the basis of compact, affordable, and sensitive analyzers for real-sample analysis. Isoprene and sulfur compounds in breath and atmospheric samples have been successfully measured by coupling with a small collection system. Short-term (5 min) sorbent collection enhances the CL signal and considerably reduces interference. For sulfur gas analysis, methyl mercaptan and dimethyl sulfide can be separated on the same column that is used for collection. Waterborne arsenic is measured by automated arsine generation and CL reaction of arsine and ozone. In addition to gas-phase CL, more recent efforts towards the determination of gases by CL generated at solid/gas and liquid/gas interfaces are also discussed.     

化学发光法测定轻质油品中痕量氮

使用ANTEKg000元素分析仪，微量注射器手动进样的方式测量石脑油馏分的痕量氮。结果表明，测定结果的相对标准偏差不大于5％，相对误差在±10％以内，具有操作简捷、准确度高、重复性好以及高选择性等优点，适用于痕量氮的测定。     

流动分析仪法快速测定湿法磷酸中五氧化二磷

选择AA3型流动分析仪,运用在线稀释系统及片段流动分析技术测定湿法磷酸中五氧化二磷含量。结果显示,试样溶液中五氧化二磷在0-400mg／L范围内线性良好。与重量法比对结果接近,绝对偏差在0．33％以内。重现性良好,10次重复测定相对标准偏差为0．31％。准确度高,加标回收率在98．9％-102．5％之间。     

微库仑法测定柴油硫含量条件的优化探讨

对WK-2D型微库仑仪进行调试.从进样量、进样速度、气体流量、炉温4个方面讨论操作因素对微库伦法测定样品硫含量的影响,并确定最优操作条件.在优化条件下,对加标直馏柴油样品进行精密度和回收率考察.结果表明：进样量为1.3μL,进样速度为38档,氮气流量为260 mL/min,氧气流量为150 mL/min,汽化段温度为750℃,燃烧段温度为850℃,稳定段温度为650℃操作条件下测得直馏柴油硫含量误差低,重复性好.加标回收率在99％～102％,RSD＜1％.该方法简单、快速、准确,适合大批量直馏柴油样品的测定.     

水泥中硫的高频红外分析方法研究

采用高频红外吸收法测定了水泥中硫的含量,并对样品作测定前的预处理(物理处理),在测定中选用复合型助熔剂,解决了高频感应炉中因顶吹氧气流的作用而导致的样品喷溅问题。该法可准确测定水泥中0.001％～5％的硫,回收率为98.6％～102.5％,RSD为0.78％～1.35％。     

The extraction of sulfate sulfur from coals by organic acids

Determination of sulfate sulfur in coal has been done by using organic acids, namely: acetic acid, oxalic acid and tartaric acid. The results have been compared with those of the ASTM HCl method. It is found that 0.5 M tartaric acid is a suitable reagent by which sulfate sulfur can be effectively extracted. Minor increases of sulfate sulfur in the tartaric acid extraction over that of HCl extraction may be correlated with the solubility of sulfate minerals which seem to be unleached with the mineral acid. This has been verified by studying the solubilities of gypsum and pyrite in the tartaric acid solution. Increased solubilities of gypsum and of sulfate obtained from pyrite have been found as the concentration of tartaric acid is increased. The variation of sulfate sulfur content in the extractions of 0.5 M tartaric acid and 4.8 M HCl is not significant. As the mineral acid could degrade the organic sulfur (which can affect its determination, calculated by difference), the use of tartaric acid is strongly recommended for the determination of sulfate sulfur in coal.     

SKALAR San++连续流动分析仪同时检测水源水中总氮和总磷

实验建立了采用SKALAR San++连续流动分析仪同时检测水源水中总氮和总磷的分析方法,其中总氮方法检出限为0.05 mg/L,纯水加标回收率为94.0%~104%,相对标准偏差RSD为0.0%~0.07%;总磷方法检出限为0.009mg/L,纯水加标回收率为91.0%~106%,相对标准偏差RSD为0.0%~0.7%,均符合工作要求。通过对比分析,该方法较传统手工方法具有明显优势:可以直观图谱查看结果,可以连续监测水源水中总氮和总磷的变化,实现快速检测,对提高水源水质监测预警具有重要意义。     

利用全自动定氮仪测定硝化棉的含氮量

采用自行研制的全自动定氮仪测定硝化棉的含氮量,研究了样品前处理条件、全自动定氮仪实验参数对检测结果的影响;讨论了实验的准确性与重复性,对全自动定氮仪法与传统合金还原法进行了比较。结果表明,样品前处理采用石墨炉加热,梯度升温的皂化模式;最佳实验参数为:蒸汽体积分数80%、预热30s、还原反应7min、硼酸体积35mL、蒸馏时间8min;与传统合金还原法相比,采用全自动定氮仪检测硝化棉含氮量的方法用时少、操作简单,自动化程度高,减少了人为误差的影响,可保证结果的精度和准确性。     

不同密度级高硫煤质量分布状况

以北宿、洛阳等两地高硫煤为样品按照国标（GB／T478—2001）进行了浮沉试验,并对两煤样进行了不同密度级煤的质量（灰分、比磁化率、硫分）状况的测定;结果表明随着密度级的增加,煤的灰分和比磁化率均逐渐增大,而硫分在各密度级的分布同煤种有关,缺乏普遍规律可循,与低密度级相比高密度级高硫煤的煤质普遍较差。     

热分解前处理结合分光光度法快速测定土壤中的硫

通过高温热解将硫从土壤中分离出来,富集到吸收液,利用可见光分光光度法进行测定。对热分解系统参数进行了优化,优化后的参数为:管式炉温度1 000℃,热分解时间35 min,载气流量0.1 L/min,吸收液浓度0.02 mol/L,吸收液体积20 mL。利用累积吸收的方法获得方法检出限为0.006 mg/g,降低了该方法的检出限,提高了检测灵敏度。用于国家标准物质(GBW07425,GBW07454和GBW(E)070041)及3份实际土壤样品测定,结果与标准值相符,对实际土壤的硫加标回收率92.4%~107.5%。此方法能够快速、准确地进行土壤中硫的测定。     

微库仑法测定石油及石油产品中的硫含量

在石油化工生产过程中,硫含量的测定是需要严格控制的一项重要指标,也是与发动机的腐蚀及环保排放有关的重要项目。硫的存在还降低了油品的氧化安定性,,使油品颜色变深,产生特殊的气味和讨厌的沉渣而降低油品的质量。炼厂及石油化工装置排放气中的硫化氢、二氧化硫,在空气中还会形成酸雨,污染环境,破坏生态平衡,因此硫含量分析至关重要。分析硫常用的方法有很多:燃灯法、氧弹法、氧瓶燃烧法、微库仑法和荧光法等。本文就微库仑法灵敏度、快速、准确的特点,通过大量的实验,针对各种影响因素进行对比和研究,找到了最佳的分析条件,并选择校正曲线法建立汽油、柴油和重油中硫分析方法。试验表明:上述方法对于不同石油产品中显示出良好的选择性(重复性、再现性和灵敏度),满足了生产过程中不同石油产品中硫含量的检测需要。     

燃烧中和滴定法测定钢中低硫

探讨了用燃烧中和滴定法准确测定钢中低硫的条件 ,即助熔剂、氧气流量和时间、燃烧炉温度、吸收液颜色的选择和控制。该法可满足钢中低硫 ( S<0 .0 1% )测定精度要求     

红外光谱法测定生物质燃料中全硫的研究

建立红外光谱法测定生物质燃料中全硫含量的方法,采用标准样品校正仪器,拟合校正曲线,研究了该方法的准确度和精密度。结果表明,全硫含量在0%~4.45%范围内,测量值和实际值硫含量线性关系良好,用标准加入法进行回收率实验对方法的准确度进行考察,相对标准偏差为0.76%~1.52%,加标回收率为99.44%~99.89%。与其他检测方法比较,该方法操作简单,检测时间短,自动化程度高。