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fanxiaojuan金蟲(chóng) (小有名氣)
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[求助]
DNS試劑配制3,5-二硝基水楊酸不溶解怎么辦?
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3,5-二硝基水楊酸不溶解,有人說(shuō)加水楊酸和氫氧化鈉的間隔時(shí)間要短以免沉淀,甚至可以先加氫氧化鈉,也有說(shuō)法氫氧化鈉必須后加以免沉淀,但我兩種方法都試過(guò),還是不溶解,怎么辦? 采用以下配方:稱(chēng)取酒石酸鉀鈉182.0g,溶于500mL蒸餾水中,加熱(不超過(guò)50℃),于熱溶液中依次加入3,5-二硝基水楊酸6.3g,NaOH 21.0g,苯酚5.0g,無(wú)水亞硫酸鈉5.0g,攪拌至溶解完全,冷卻后用蒸餾水定容至1000mL,貯存于棕色瓶中,室溫保存。 |
鐵桿木蟲(chóng) (著名寫(xiě)手)
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Preparation of DNS (Dinitrosalycyclic Acid) solution Different ingredients used for the preparation of DNS solution are as follows: 1). Distilled water 1416 ml 2). 3.5 Dinitrosalycyclic Acid 10.6 g 3). NaOH 19.5 g The above ingredients were dissolved gently in water bath at 80°C until a clear solution was obtained. Then the following chemicals were added. 4). Rochelle salt (sodium potassium tartrate) 300g 5). Phenol (melted at 60°C) 7.5 ml 6). Sodium meta bisulphate 8.3g After dissolving the above ingredients, the solution was filtered through a large coarse sintered glass filter and stored at room temperature in an amber colored bottle to avoid photo oxidation. 按這個(gè)方法配,一定會(huì)溶,以前我也是遇到不溶解,后來(lái)改用這個(gè)方法,屢試不爽 |

木蟲(chóng) (小有名氣)
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新蟲(chóng) (正式寫(xiě)手)

專(zhuān)家顧問(wèn) (知名作家)
生物大分子降解酶
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鐵蟲(chóng) (初入文壇)

金蟲(chóng) (小有名氣)
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至尊木蟲(chóng) (知名作家)
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我們的方法和6樓相同,只是體積放大了10倍,沒(méi)有出現(xiàn)不溶解現(xiàn)象。 將6.3g DNS和262mL 2M NaOH溶液,加到500mL含有185g酒石酸鉀鈉的熱水溶液中,再加5g結(jié)晶酚和5g亞硫酸鈉,攪拌溶解,冷卻后加蒸餾水定容至1000mL,貯于棕色瓶中,放置7 d后使用。 |
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