共查询到19条相似文献,搜索用时 218 毫秒
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聚合物微球调驱技术已经在华北油田各采油厂广泛应用,取得较好效果。由于油田产出液中存在线性聚丙烯酰胺(HPAM)的干扰,聚合物微球含量难以准确测定。针对这一问题,利用紫外分光光度法,采用特定波长下不同浓度样品线性拟合曲线斜率最大化方法,优选最佳检测波长;采用部分遮蔽紫外响应的方法,向参比及待测溶液中添加含铵离子的遮蔽剂以消除HPAM的影响。结果表明,紫外分光光度法检测聚合物微球的最佳波长为196 nm。在遮蔽剂加量为2 g/L、聚合物微球质量浓度为1~200 mg/L时,明确了吸光度与微球浓度的线性关系,相关判定系数为0.9987,实现了HPAM干扰下聚合物微球含量的定量检测。 相似文献
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采用紫外分光光度法评价石油烃降解菌的降解能力 总被引:2,自引:0,他引:2
为克服摇瓶培养过程中石油烃降解菌代谢产物对紫外分光光度法比色的干扰,建立了离心前处理—超声波萃取—紫外分光光度法,验证并评价了石油烃降解菌Acinetobacter sp RP-1的降解能力。结果表明,在254 nm最佳吸收波长下,以沸程为30~60℃的石油醚为萃取剂,在石油烃质量浓度为5~300 mg/L范围内,吸光度与石油烃浓度间符合比尔定律关系,工作曲线的相关系数为0.999 8;采用离心前处理和超声波萃取处理样品,石油烃的平均回收率为98.9%,相对标准偏差为1.78%,最低检出限为0.713 mg/L;可检测出无机盐培养基中低至0.001%的残余烃。 相似文献
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考查了不同含油量浓度与其荧光强度的关系,以及原油组分不同时荧光强度和含油量的线性关系情况,比较了紫外一荧光法和可见光分光光度法测油的灵敏度和精密度。实验结果表明:原油的荧光强度和浓度在高浓度范围时,由于荧光的猝灭作用导致两者线性关系差,难以用标准曲线法进行定量分析。然而在低浓度(0mg/L~100mg/L)时,选用的3种原油的荧光强度和浓度线性关系的R2均在0.99以上:其线性关系的浓度范围与原油组分有关,饱和分含量较高的南海标准油C,在0mg/L-160mg/L的浓度范围时线性关系仍然较好;与传统的分光光度法相比,荧光法精密度更高,其测量的相对标准偏差为3.6%,远远小于分光光度法测得的16.81%。 相似文献
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为了测定页岩油开采压裂返排液中油含量,探索了一种新的紫外-可见分光光度法,此方法选用实验室较为常用的石油醚作为萃取剂,免除了紫外方法中对萃取剂较为复杂的脱芳处理,优化了实验步骤,使得测定过程更加简洁高效,同时降低了对实验者的健康伤害。依据朗伯-比尔定律,利用紫外-可见分光光度计扫描页岩油-石油醚体系全波长范围的吸收光谱,选择了285 nm作为检测波长。提取现场采出液制备的标准页岩油精确配置系列标准浓度溶液,根据实验数据,用最小二乘法拟合曲线列出标准曲线方程。同时,对方法的检出限、准确度和精密度进行了实验分析,实践证明该方法简单可行,测得的数据准确可靠。 相似文献
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基于偏最小二乘法的氨基甲酸甲酯和尿素含量的同时测定 总被引:1,自引:1,他引:0
开发了一种同时测定氨基甲酸甲酯与尿素混合物的方法。用紫外可见光分光光度计测定混合物的吸光度,采用偏最小二乘法模型对吸光度进行校正,并预测试样各组分的浓度。考察了测定条件对测定结果的影响。得到的最优测定条件为:显色剂用量20mL,盐酸用量12mL,显色时间15min,试剂加入顺序盐酸→显示剂→试样,测定波长范围410~445nm。计算结果与实际值的误差很小,平均回收率接近于100%,相对均方根偏差小于4%。该方法可不经分离同时测定各组分的浓度,准确度高,过程简单,运算快速。 相似文献
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分光光度法测定萃取残液中的微量氯仿 总被引:2,自引:0,他引:2
研究了分光光度法检测水体中的微量氯仿,确定了试样的制备和处理方法。氯仿的最大吸收波长为530nm,相关线性范围为0~60mg/L。试样制备过程显色清晰,色差稳定。检测方法简便、快捷、实用,适用于生产过程中的在线检测及水体监测。水中溶解的氯仿经萃取回收后,质量浓度可由6000~7000mg/L降至230~250mg/L,氯仿回收率达96%。 相似文献
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紫外分光光度法测定石油产品中芳烃含量 总被引:3,自引:0,他引:3
介绍了紫外分光光度法测定芳烃含量,在等吸光点212nm波长处,以间二甲苯为标准物,不经分离,直接测定。试验结果表明,芳烃含量在1~15μg/ml内遵从比耳定律,回收率达96.5%~102.5%,相对标准偏差小于0.8%,灵敏度和选择性优于其它方法。该法用于石油产品中芳烃的测定,结果令人满意,并与经典的色谱法分析结果吻合。 相似文献
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通过对硼酸—碘体系的显色稳定性及聚乙烯醇(PVA)溶液的紫外吸收波长进行系统地考察,建立了聚氯乙烯离心母液工业废水中PVA含量的紫外分光光度分析方法。试验结果证明,检测波长690nm,相关系数0.9998,回收率97%~104%。该方法可以直接测定废水中PVA含量,具有操作简便、选择性好、准确度高的特点。 相似文献
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《Food Control》2007,18(1):18-22
The potential of the ultraviolet and visible (UV/VIS 200–800 nm) transmittance method to inspect the internal quality (freshness) of intact chicken egg was investigated. The nondestructive measurement optical models for egg quality were also studied. Three hundred and fifty chicken egg samples were used for measuring its freshness and spectral collection during egg storage time. Two correlation models between Haugh unit and the storage time, the yolk coefficient and the storage time were developed with the correlation coefficients of 0.994, 0.987, respectively. A relationship between the intact egg transmittance and the storage time was also developed with the correlation coefficients of 0.935 at the sensitive spectral wavelength of 465 nm. It was concluded that: the nondestructive inspection of egg freshness by transmittance properties is feasible in the range of 400–600 nm, while it is impossible to inspect egg freshness in the range of 200–400 nm due to the low transmittance. 相似文献
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《Food Control》2014
Perceptual quality and food safety of grape products like wine is generally impaired by grape rot. Commonly applied visual inspection for quality assessment remains subjective. However, conventional analytical determinations are tedious and time-consuming. In contrast, near infrared/visible (NIR/VIS) spectroscopy is an objective and rapid alternative. An industrial spectrometer especially designed for on-line process integration was applied in laboratory configuration to evaluate the feasibility of the prediction of ergosterol and 12 further quality-associated parameters in grape mashes. Calibration models were established, validated, and evaluated. Spectral ranges used were 450–850 nm (VIS) and 1050–1650 nm (NIR). The regression method applied was partial least squares (PLS) regression. Calibrations at best suitable for discriminating low and high values were obtained for gluconic, acetic, tartaric, and titratable acids contents, pH value, ethanol content, and laccase activity. Therefore, for these parameters limits of NIR/VIS spectroscopy may be revealed. Calibrations for semi-quantitative predictions or rough estimations were obtained for fructose, glucose, and malic acid contents. Best performance suitable for quantitative predictions was achieved for relative density, glycerol, and ergosterol contents. The industrial spectrometer proved to perform similar to a research laboratory spectrometer. Consequently, a future on-line implementation of NIR/VIS spectrometers in wineries may be a valuable and reliable tool for rapid grape quality assessment at reception. Particularly, ergosterol content prediction proved to be a promising measure for efficient and immediate quality control and management, respectively. Wine quality and food safety may be increased. Fair and incentive pricing of delivered grapes may be enabled. 相似文献
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采用UV - 91 0 0型紫外可见分光光度计 ,测定了由植物油脂制得的共轭亚油酸、共轭亚油酸甲酯、共轭亚油酸三甘酯在不同浓度时在 2 0 0nm - 30 0nm的吸光度 ,绘制出样品在不同浓度时的吸光度曲线 ,找出适宜的浓度范围 ,用MicrocalSoftwareOriginVersion 4.0做回归分析 ,由线性回归给出样品浓度和吸光度的线性关系 ,为对实验结果进行检验和校正 ,采用惠普 845 2A二极管阵列分光光度计测定了同一批样品在不同浓度范围内的吸光度 ,利用PEAutosystemXL -TurboMass测得样品中共轭亚油酸准确浓度 ,结合回归系数给出了用紫外可见分光光度计快速测定样品中共轭亚油酸含量的经验公式 相似文献