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普瑞巴林我们用0.01mol/l磷酸氢二钠溶液:甲醇:乙腈=80:15:5来检测杂质,其中出峰在2.733min的杂质重现性很差,同一批产品检测结果都不一样,最大结果相差0.1%,请问该怎么解决呢?
[color=#444444]1) API中性,分子量约为150,分子中一个氨基,一个羧基;[/color][color=#444444]2) 有关物质HPLC法,C18色谱柱,初始检测无问题,一段时间后,开始是主峰分叉,继而所有峰分叉;[/color][color=#444444]3) 目前可查到的文献及国外药典标准中,有关物质检测都用的是C18柱。[/color][color=#444444]4) 流动相:[/color][color=#444444]第一种:1.36g/L磷酸二氢钾(5M氢氧化钾调节pH值至6.5)-甲醇,梯度洗脱:[/color][color=#444444]t/min pH6.5磷酸二氢钾 甲醇[/color][color=#444444]0 95 5[/color][color=#444444]40 95 5[/color][color=#444444]80 40 60[/color][color=#444444]85 40 60[/color][color=#444444]86 10 90[/color][color=#444444]96 10 90[/color][color=#444444]97 95 5[/color][color=#444444]110 95 5[/color][color=#444444]上述盐溶液层根据文献,尝试更换过pH6.5磷酸氢二铵溶液,结果与磷酸二氢钾一致。[/color][color=#444444]也曾尝试改变盐溶液浓度。[/color][color=#444444]第二种,将pH6.5磷酸二氢钾与甲醇预混后,再进行梯度洗脱:[/color][color=#444444]t/min pH6.5磷酸二氢钾-甲醇(96:4) pH6.5磷酸二氢钾-甲醇(4:6)[/color][color=#444444]0 100 0[/color][color=#444444]40 100 0[/color][color=#444444]80 0 100[/color][color=#444444]90 0 100[/color][color=#444444]91 100 0[/color][color=#444444]110 100 0[/color][color=#444444]求助:为什么峰会分叉?什么原因导致色谱柱寿命如此之短?如何解决?[/color][color=#444444][color=#444444]1、每次运行完都会清洗色谱柱[/color][color=#444444]2、盐项无异常现象[/color][color=#444444]3、新色谱柱使用不到半个月,就不行了,但柱压并没有很大的变化[/color][color=#444444]4、柱温35℃[/color][color=#444444]5、塔板数会随着使用时间而降低[/color][/color]
Peripheral and central neuropathic pain: LYRICA is used to treat long lasting pain caused by damage to the nerves. A variety of diseases can cause peripheral neuropathic pain, such as diabetes or shingles. Pain sensations may be described as hot, burning, throbbing, shooting, stabbing, sharp, cramping, aching, tingling, numbness, pins and needles. Peripheral and central neuropathic pain may also be associated with mood changes, sleep disturbance, fatigue (tiredness), and can have an impact on physical and social functioning and overall quality of life. Epilepsy: LYRICA is used to treat a certain form of epilepsy (partial seizures with or without secondary generalisation- epileptic fits starting on one specific part of the brain) in adults. Your doctor will prescribe LYRICA for you to help treat your epilepsy when your current treatment is not controlling your condition. You should take LYRICA in addition to your current treatment. LYRICA is not intended to be used alone, but should always be used in combination with other anti-epileptic treatment. Generalised Anxiety Disorder: LYRICA is used to treat Generalised Anxiety Disorder (GAD). The symptoms of GAD are prolonged excessive anxiety and worry that are difficult to control. GAD can also cause restlessness or feeling keyed up or on edge, being easily fatigued (tired), having difficulty concentrating or mind going blank, feeling irritable, having muscle tension or sleep disturbance. This is different to the stresses and strains of everyday life.