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Determination of Vitamin B12 Using Differential Pulse Polarography
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作者 Sukru Kalayci Ulku Unal Guler Somer 《American Journal of Analytical Chemistry》 2020年第5期187-196,共10页
Vitamin B12 is a type of vitamin also known by the name cobalamin. B12 is involved in many metabolism activities, including DNA synthesis, nervous system, red blood formation and immune system. Therefore, we chose the... Vitamin B12 is a type of vitamin also known by the name cobalamin. B12 is involved in many metabolism activities, including DNA synthesis, nervous system, red blood formation and immune system. Therefore, we chose the Differential Pulse Polarography (DPP) method is that has a high sensitivity for the determination of vitamin B12. This determination was possible with cobalt present in vitamin B12 structure. Since Co(III) is formed from the oxidation of the vitamin, its polarographic behavior had to be determined in various electrolytes such as acetate, borate, phosphate and ammonia. The polarograms of Co(III) were taken in these electrolytes in which 1.0 M NH3/ (pH = 9.8) and 1.0 M AcOH/AcO- (pH = 4.0) were found as the most suitable electrolytes. This method was successfully applied vitamin of B12 determination in a 1 mL ampoule with high precision. The LOD was found as 3.7 × 10-7 for instead of (S/N = 3). Besides Co(III), interference effects of Zn(II), Ni(II), Cr(III), Fe(III), Cu(II), Cd(II) and Se(IV) were also studied. It was found that only Zn(II) peak had an overlap Co(III) peak in ammonium buffer. This problem could be solved by working in 1.0 M AcOH/AcO- (pH = 4.0) buffer. B12, which is 1000 μg in 1 mL vitamin ampoule, was found for 4 measurements as 999 ± 15 μg as a result of 95% confidence interval. 展开更多
关键词 vitamin b12 determination COBALT Differential Pulse Polarography Interferences Studies
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Long-term metformin therapy and vitamin B12 deficiency: An association to bear in mind 被引量:8
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作者 Marco Infante Martina Leoni +1 位作者 Massimiliano Caprio Andrea Fabbri 《World Journal of Diabetes》 SCIE 2021年第7期916-931,共16页
To date,metformin remains the first-line oral glucose-lowering drug used for the treatment of type 2 diabetes thanks to its well-established long-term safety and efficacy profile.Indeed,metformin is the most widely us... To date,metformin remains the first-line oral glucose-lowering drug used for the treatment of type 2 diabetes thanks to its well-established long-term safety and efficacy profile.Indeed,metformin is the most widely used oral insulinsensitizing agent,being prescribed to more than 100 million people worldwide,including patients with prediabetes,insulin resistance,and polycystic ovary syndrome.However,over the last decades several observational studies and meta-analyses have reported a significant association between long-term metformin therapy and an increased prevalence of vitamin B12 deficiency.Of note,evidence suggests that long-term and high-dose metformin therapy impairs vitamin B12 status.Vitamin B12(also referred to as cobalamin)is a water-soluble vitamin that is mainly obtained from animal-sourced foods.At the cellular level,vitamin B12 acts as a cofactor for enzymes that play a critical role in DNA synthesis and neuroprotection.Thus,vitamin B12 deficiency can lead to a number of clinical consequences that include hematologic abnormalities(e.g.,megaloblastic anemia and formation of hypersegmented neutrophils),progressive axonal demyelination and peripheral neuropathy.Nevertheless,no definite guidelines are currently available for vitamin B12 deficiency screening in patients on metformin therapy,and vitamin B12 deficiency remains frequently unrecognized in such individuals.Therefore,in this“field of vision”article we propose a list of criteria for a cost-effective vitamin B12 deficiency screening in metformin-treated patients,which could serve as a practical guide for identifying individuals at high risk for this condition.Moreover,we discuss additional relevant topics related to this field,including:(1)The lack of consensus about the exact definition of vitamin B12 deficiency;(2)The definition of reliable biomarkers of vitamin B12 status;(3)Causes of vitamin B12 deficiency other than metformin therapy that should be identified promptly in metformin-treated patients for a proper differential diagnosis;and(4)Potential pathophysiological mechanisms underlying metformin-induced vitamin B12 deficiency.Finally,we briefly review basic concepts related to vitamin B12 supplementation for the treatment of vitamin B12 deficiency,particularly when this condition is induced by metformin. 展开更多
关键词 METFORMIN vitamin b12 deficiency Metformin-induced cobalamin deficiency Diabetes Type 2 diabetes PREDIABETES Screening criteria NEUROPATHY ANEMIA
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Vitamin B12 Screening in Cervical Spine Surgery Patients 被引量:1
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作者 Abdullah Tolaymat Moataz Abbara +2 位作者 M. Sami Walid Mohammed Ajjan Joe Sam Robinson Jr 《Neuroscience & Medicine》 2011年第2期149-153,共5页
Introduction Vitamin B12 is very vital for the nervous system. Its deficiency can manifest with neurological symptoms like pain and paresthesias and in severe cases may cause not completely restorable neurological dam... Introduction Vitamin B12 is very vital for the nervous system. Its deficiency can manifest with neurological symptoms like pain and paresthesias and in severe cases may cause not completely restorable neurological damage, especially in elderly patients. Methods The charts of 702 patients who underwent cervical spine surgery retrospectively reviewed and data collected . All patients were preoperatively seen by an internist who ordered Vit B12 levels for some of them. We used two thresholds for the diagnosis of vitamin B12 deficiency, 200 and 300 pg/mL as recommended by Yao et al. 1992. Data were also collected on gender, payor status, myelopathy, hemoglobin level, corpuscular parameters and glycosylated hemoglobin level (HbA1c). Vitamin B12 levels were compared between patients with HbA1c levels ≥ 6.1% and <6.1%. Differences between patients ≥ and < than the median age were studied. The median age of the patient cohort was 52. Results Hemoglobin level was recorded for 659 patients. Vit B12 levels were ordered for 291 patients only. Overall, 13.7% had decreased hemoglobin level (anemia), 30.2% had decreased Vit B12 levels by the 300 threshold, 6.9% had decreased Vit B12 levels by the 200 threshold, 6.3% decreased MCV (microcytosis), and 2.8% increased MCV (macrocytosis). Only four patients (0.7%), of whom older than 52, had decreased hemoglobin level and increased MCV (macrocytic anemia) and one patient (0.4%), who was also older than 52, had decreased hemoglobin level, increased MCV and Vit B12 level < 200 pg/mL (macrocytic anemia duo to Vit B12 deficiency). Dividing the patient sample into three age groups, <40, 40-59, and ≥ 60 years, we investigated the trend of cobalamin deficiency by age and found an increase in cobalamin deficiency after 40 from 0% to 7.4% (200 threshold). Uninsured patients (25%) using the 200 pg/mL threshold and workers’ compensation (54.5%) and uninsured patients (50.0%) had the highest rate of Vit B12 deficiency using the 300 pg/mL threshold. The few patients with macrocytic anemia (N=4) and macrocytic anemia due to Vit B12 deficiency (N=1) had health coverage. Conclusion Vit B12 deficiency in cervical spine surgery patients may not necessarily mean macrocytic anemia but may precede macrocytic anemia. Therefore, Vit B12 deficiency screening on the preoperative visit is warranted especially in uninsured or older patients or both. Preoperative treatment may be indicated and correlation with postoperative outcome is suggested for future research. 展开更多
关键词 vitamin b12 cobalamin CERVICAL SPINE Surgery
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Determination of Vitamin B<sub>12</sub>in Chinese Black Tea Leaves 被引量:1
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作者 Fei Teng Tomohiro Bito +2 位作者 Shigeo Takenaka Yukinori Yabuta Fumio Watanabe 《Food and Nutrition Sciences》 2014年第14期1326-1332,共7页
We determined vitamin B12 content of Chinese black tea leaves using a microbiological assay based on Lactobacillus delbrueckii ATCC 7830. Trace levels (0.25 - 0.69 μg/100g dry weight) of vitamin B12 were detected in... We determined vitamin B12 content of Chinese black tea leaves using a microbiological assay based on Lactobacillus delbrueckii ATCC 7830. Trace levels (0.25 - 0.69 μg/100g dry weight) of vitamin B12 were detected in Pu’er, Fu, and Brick tea leaves. However, vitamin B12 content (0.06 - 1.37 μg/100g dry weight) of Ryubao tea leaves significantly varied. To determine whether Chinese black tea leaves contain vitamin B12 or other corrinoid compounds that are inactive in humans, corrinoid compounds were purified from Ryubao tea by an immunoaffinity column chromatography and vitamin B12 was identified by liquid chromatography-electrospray ionization/tandem mass spectrometry. Vitamin B12 content in the tea drink prepared from Ryubao tea leaves was very low (0.8 ng/100mL). Our results indicate that Chinese black tea is usually not a good source of B12, although Ryubao tea leaves with the highest B12 content may be utilized as a source of this vitamin for vegerarians. 展开更多
关键词 CHINESE Black TEA LEAVES cobalamin Ryubao TEA vitamin b12
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火焰原子吸收光谱法测定三种维生素B_(12)片中钴的含量 被引量:1
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作者 苏畅 汪子涵 黄际宇 《生物化工》 CAS 2024年第1期126-128,共3页
目的:采用空气-乙炔火焰原子吸收光谱法测定维生素B_(12)片中钴的含量。方法:检测波长为240.63 nm,灯电流为4.0 mA,狭缝宽度为0.2 nm,燃气流量为1.3 L/min,助燃气流量为13.5 L/min,采用标准曲线法测定并对比三种维生素B_(12)片中钴的含... 目的:采用空气-乙炔火焰原子吸收光谱法测定维生素B_(12)片中钴的含量。方法:检测波长为240.63 nm,灯电流为4.0 mA,狭缝宽度为0.2 nm,燃气流量为1.3 L/min,助燃气流量为13.5 L/min,采用标准曲线法测定并对比三种维生素B_(12)片中钴的含量。结果:钴浓度在0.01~0.20 mg/L时与吸光度的线性关系良好(r=0.9994),加样回收率在97.5%~98.3%。3个批次样品的钴含量在标示量的97.8%~98.9%。结论:所用方法操作简便、结果准确并且干扰较少、具有稳定性,可用于维生素B_(12)片钴含量测定及质量控制。 展开更多
关键词 火焰原子吸收光谱法 维生素b12 含量测定
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一种简便、快速测定发酵液中V_(B_(12))含量的方法 被引量:10
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作者 张玉明 王雷 +2 位作者 王云山 张利平 苏志国 《食品与发酵工业》 CAS CSCD 北大核心 2005年第1期123-125,共3页
文中探索了一种不经氰化物转化而直接使用HPLC测定发酵液中维生素B12 (包括羟基钴胺素、脱氧腺苷钴胺素和甲基钴胺素 )的检测方法。将发酵液离心取菌体 ,样品预处理后进样分析 ,采用乙腈和醋酸钠缓冲液为流动相。此方法能够精确检测上... 文中探索了一种不经氰化物转化而直接使用HPLC测定发酵液中维生素B12 (包括羟基钴胺素、脱氧腺苷钴胺素和甲基钴胺素 )的检测方法。将发酵液离心取菌体 ,样品预处理后进样分析 ,采用乙腈和醋酸钠缓冲液为流动相。此方法能够精确检测上述 3种钴胺素 ,并且重复性好、分析速度快 ,可应用于工业发酵生产维生素B12 的过程监控和检测。 展开更多
关键词 维生素b12 含量 法能 腺苷钴胺 HPLC测定 Vb12 缓冲液 发酵液 甲基 发酵生产
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食品中VB_(12)检测方法研究进展 被引量:9
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作者 周迅雷 张志国 +2 位作者 褚庆环 生庆海 张佳程 《食品与发酵工业》 CAS CSCD 北大核心 2008年第11期131-134,共4页
VB12是重要的B族维生素,在食品中的含量很低。文中论述了近年来VB12检测方法的研究现状,分析了各种检测方法的特点,并根据食品特点对VB12检测方法的发展提出了展望。
关键词 Vb12 钴胺素 检测方法
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维生素B_(12)的研究及其进展 被引量:30
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作者 罗祎 郝常明 《中国食品添加剂》 CAS 2002年第3期15-18,30,共5页
本文对维生素B12 的生理特性、产生菌、生物合成途径 ,以及发酵生产和测定方法进行了详尽的阐述 ,并对目前维生素B12
关键词 维生素b12 合成 发酵 测定方法 生理特性
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1%维生素B_(12)干粉的HPLC测定 被引量:3
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作者 钱维清 邱在峰 《中国医药工业杂志》 CAS CSCD 北大核心 1997年第8期367-369,共3页
采用十八烷基硅烷键合硅胶柱,以HPLC外标法测定1%VB12干粉含量。线性范围为10~200μg/ml(r=0.9999),平均回收率为99.90%,RSD为0.33%。与UV法、微生物比浊法比较,方法简便、快速、灵... 采用十八烷基硅烷键合硅胶柱,以HPLC外标法测定1%VB12干粉含量。线性范围为10~200μg/ml(r=0.9999),平均回收率为99.90%,RSD为0.33%。与UV法、微生物比浊法比较,方法简便、快速、灵敏度和重现性好。 展开更多
关键词 干粉 HPLC 维生素b12
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维生素B_(12)溶液鼻粘膜吸收的研究 被引量:2
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作者 杨建红 张钧寿 +1 位作者 史雪燕 孙颖 《中国药科大学学报》 CAS CSCD 北大核心 2002年第1期17-20,共4页
目的 :研究维生素 B1 2 溶液鼻粘膜吸收规律。方法 :以大鼠在体鼻循环法为实验模型 ,考查循环液浓度不同时 ,维生素 B1 2 鼻粘膜吸收规律。结果 :考察了 0 .2 5 ,0 .5 ,1 mg/ml三种浓度的维生素 B1 2 溶液鼻粘膜吸收规律 ,表明不同浓度... 目的 :研究维生素 B1 2 溶液鼻粘膜吸收规律。方法 :以大鼠在体鼻循环法为实验模型 ,考查循环液浓度不同时 ,维生素 B1 2 鼻粘膜吸收规律。结果 :考察了 0 .2 5 ,0 .5 ,1 mg/ml三种浓度的维生素 B1 2 溶液鼻粘膜吸收规律 ,表明不同浓度的维生素 B1 2 鼻粘膜吸收速度为一常数。结论 :维生素 B1 2 溶液鼻粘膜吸收机制为被动扩散 ,吸收符合一级动力学 ,吸收速度常数 K为 0 .0 2 4 41 min- 1 。 展开更多
关键词 维生素b12 在体鼻循环法 鼻粘膜 吸收速度常数 研究
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褶合光谱法测定治癫三号中主药的含量 被引量:4
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作者 光新兰 金文祥 王瑞菊 《武警医学》 CAS 2002年第4期197-199,共3页
目的 不经分离直接测定卡马西平和维生素B6的含量。方法 采用褶合光谱法。结果 二组分的回收率和RSD分别为 99 72 % ,1 6 1% ;99 6 9% ,2 35 %。结论 本法结果可靠、准确 。
关键词 褶合光谱法 维生素B6 卡马西平 含量 测定
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改进HPLC法测定注射用多种维生素(12)中维生素B_(12)的含量 被引量:4
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作者 徐家根 刁岩忠 《中国药房》 CAS 北大核心 2016年第36期5159-5161,共3页
目的:改进高效液相色谱法测定注射用多种维生素(12)中维生素B12的含量。方法:采用高效液相色谱法。色谱柱为Kromasil 100-5 C18,流动相为水(用10%稀磷酸调节p H为4.5)-乙腈(梯度洗脱),流速为1.2 ml/min,检测波长为361 nm,柱温... 目的:改进高效液相色谱法测定注射用多种维生素(12)中维生素B12的含量。方法:采用高效液相色谱法。色谱柱为Kromasil 100-5 C18,流动相为水(用10%稀磷酸调节p H为4.5)-乙腈(梯度洗脱),流速为1.2 ml/min,检测波长为361 nm,柱温为35℃,进样量为50μl。结果:维生素B12检测进样量线性范围为15.0345.09 ng(r=0.999 9);精密度、稳定性、重复性试验的RSD〈1%;回收率为99.31%100.90%(RSD=0.42%,n=9)。结论:该方法简便、准确、灵敏度高、重复性好,可用于注射用多种维生素(12)中维生素B12的含量测定。 展开更多
关键词 注射用多种维生素(12) 维生素b12 含量测定 高效液相色谱法 方法改进
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Effect of complex reinforcing-reducing manipulation on lower limb motion and balance disorder in patients with subacute combined degeneration of the spinal cord 被引量:2
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作者 张朝红 李旗 《Journal of Acupuncture and Tuina Science》 CSCD 2015年第3期189-193,共5页
Objective:To observe the effect of complex reinforcing [Shao Shan Huo (Mountain-burning Fire)] and reducing [Tou Tian Liang (Heaven-penetrating Cooling)] manipulations on motion and balance of the lower limbs in ... Objective:To observe the effect of complex reinforcing [Shao Shan Huo (Mountain-burning Fire)] and reducing [Tou Tian Liang (Heaven-penetrating Cooling)] manipulations on motion and balance of the lower limbs in patients with subacute combined degeneration of the spinal cord (SCD). Methods:A total of 100 SCD cases were randomly allocated into an observation group and a control group by their visit sequence, 50 cases in each group. On the basis of Western medical treatment, cases in the observation group were also treated with acupuncture therapy plus complex reinforcing-reducing manipulation; whereas cases in the control group were only treated with the same Western medical treatment as those in the observation group. Before and 2 months after treatment, kinematic parameters including muscle force, muscle tone and range of motion of the hip and knee joints were measured. In addition, balancing parameters including the path length of center of pressure (COP), peripheral area, COP path length per unit area and rectangular area were also measured before and after treatment. Results:After treatment, there were statistical intra-group differences in COP path length, peripheral area, COP path length per unit area, left-right offset, rectangular area, coefficient of stability and coefficient of weight distribution (P〈0.01). There were statistical inter-group differences in muscle force, muscle tone and range of motion of hip and knee joints (P〈0.01). The total effective rate was 83.3% in the observation group, versus 60.0% in the control group, showing a statistical difference (P〈0.05). Conclusion:Complex reinforcing-reducing manipulations can improve the lower limb motion and balance in SCD patients. 展开更多
关键词 Acupuncture therapy method of Reinforcing-reducing vitamin b12 Deficiency
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复合维生素B中B2含量的快速测定 被引量:1
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作者 李伟珍 吴定丽 +2 位作者 王琪 吴云妹 陈梓云 《化工技术与开发》 CAS 2020年第7期59-62,共4页
以高效液相色谱法测定复合维生素B中B2含量的方法为参比方法,采用近红外分析技术,结合偏最小二乘法,分别建立了药物复合维B中B2含量的定量分析模型(模型1)和保健品B族维生素中B2含量的定量分析模型(模型2)。用模型1检测药物复合维B中B2... 以高效液相色谱法测定复合维生素B中B2含量的方法为参比方法,采用近红外分析技术,结合偏最小二乘法,分别建立了药物复合维B中B2含量的定量分析模型(模型1)和保健品B族维生素中B2含量的定量分析模型(模型2)。用模型1检测药物复合维B中B2的含量,预测结果为:绝对误差在-0.10%~0.13%之间,相对误差在-4.66%~6.28%之间。用模型2检测保健品B族维生素中B2的含量,预测结果为:绝对误差在-0.01%~0.11%之间,相对误差在-3.22%~5.42%之间。建立了一种快速、准确地检测复合维生素B中B2含量的新方法。 展开更多
关键词 快速测定 复合维生素B 维生素B2 近红外光谱 最小二乘法
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复方甲硝唑片的差谱测定法 被引量:3
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作者 杜志茂 《中国医药工业杂志》 CAS CSCD 北大核心 1997年第6期265-267,共3页
采用差谱法测定复方甲硝唑片中两组分的含量,甲硝唑和维生素B6的平均回收率分别为99.9%和99.7%。RSD分别为0.14%和0.43%。方法简便,结果准确。
关键词 差谱法 甲硝唑 维生素B6 测定
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宠物食品中维生素B_(12)的快速测定 被引量:2
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作者 韩冀 石磊 +3 位作者 梁启美 陶文靖 张君超 王玉花 《食品安全导刊》 2022年第25期51-54,共4页
比较宠物食品中维生素B_(12)检测方法的差别,并评价微孔板法检测维生素B_(12)的检测性能。采用微孔板法与微生物法模拟样品与自然样品的检测试验,比较分析检测结果。微孔板法与微生物法的检测效果基本一致,微孔板法具有良好的检测性能... 比较宠物食品中维生素B_(12)检测方法的差别,并评价微孔板法检测维生素B_(12)的检测性能。采用微孔板法与微生物法模拟样品与自然样品的检测试验,比较分析检测结果。微孔板法与微生物法的检测效果基本一致,微孔板法具有良好的检测性能。同时发现维生素B_(12)的含量受加工工艺的影响较大,在高温膨化粮中的平均含量最低,仅为6.2μg/100 g,而在冻干粮中的含量最高,达到16.0μg/100 g。 展开更多
关键词 宠物食品 维生素B_(12) 微孔板法 快速测定
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微生物法检测VB_(12)的影响因素分析及优化方向进展 被引量:1
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作者 刘萍 曾慧君 +2 位作者 晏涛 向春燕 郦娟 《食品工程》 2023年第4期1-3,共3页
微生物法在VB_(12)检测中有非常广泛的应用,具有特异性好、灵敏度高等优势,但该方法也存在操作步骤复杂、对实验人员要求较高、不稳定因素较多等缺点。为解决传统微生物方法中存在的问题,对微生物法中的关键步骤进行了分析,并阐述了目... 微生物法在VB_(12)检测中有非常广泛的应用,具有特异性好、灵敏度高等优势,但该方法也存在操作步骤复杂、对实验人员要求较高、不稳定因素较多等缺点。为解决传统微生物方法中存在的问题,对微生物法中的关键步骤进行了分析,并阐述了目前其优化方向的研究进展,以期为微生物法的改进提供参考。 展开更多
关键词 VB_(12) 钴胺素 微生物法 维生素测定
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维生素B1片含量测定方法的验证 被引量:2
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作者 高雅杰 《按摩与康复医学》 2010年第24期1-2,共2页
目的:采用紫外分光光度法测定维生素B1片中维生素B1 的含量并对该方法进行验证.方法:用紫外分光光度法在246nm处测定吸光度,并用百分吸收系数法和对照品比较法计算.结果:用紫外分光光度法测定维生素B1 含量的方法专属性好;当维生素B1... 目的:采用紫外分光光度法测定维生素B1片中维生素B1 的含量并对该方法进行验证.方法:用紫外分光光度法在246nm处测定吸光度,并用百分吸收系数法和对照品比较法计算.结果:用紫外分光光度法测定维生素B1 含量的方法专属性好;当维生素B1 浓度在7.5~17.5μg/ml范围时线性关系良好,回归方程为Y=0.0411X+0.0094,线性相关系数r=1;平均回收率为99.60%,RSD=0.45%;精密度为0.76%;用百分吸收系数法计算平均标示量为101.7%,用对照品比较法计算平均标示量为104.3%.结论:用紫外分光光度法测定维生素B1片中维生素B1的含量操作简便、快速、准确、精密度好. 展开更多
关键词 紫外分光光度法 维生素B1 含量测定
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