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¿µÁøÄÚÆÛ·¹ÀÌ¼Ç Á¾ÇÕÄ«´Ù·Î±× |
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- Reference : UNI EN ISO 15476:2009, AOAC 892.01
- Tested with VELP Scientifica UDK 149 Kjeldahl Distillation Unit (Code F30200140) |
Introduction
ÀϹÝÀûÀ¸·Î ½Ä¹°Àº ½Ä¹° ÀÚü ¼ººÐÀÇ 3-4 % ¿¡ ÇØ´çÇÏ´Â ¾çÀÇ Áú¼Ò¸¦ °¡Áö°í Àִµ¥ ÀÌ´Â ´Ù¸¥ ¿µ¾ç¼Ò¿¡ ºñÇØ
»ó´çÈ÷ ¸¹Àº ¾ç¿¡ ÇØ´çÇÑ´Ù. Áú¼Ò´Â ½Ä¹°ÀÇ ±¤ÇÕ¼º ÀÛ¿ë¿¡ ¸Å¿ì Áß¿äÇÑ ¼ººÐÀ̹ǷΠ½Ä¹°Àº ammonium (NH4+),
nitrate (NO3-), urea ((NH2)2 CO) µî ´Ù¾çÇÑ ÇüÅÂÀÇ Áú¼Ò¿øÀ¸·ÎºÎÅÍ Áú¼Ò¸¦ Èí¼öÇÏ°Ô µÈ´Ù.
´ëºÎºÐÀÇ »ó¾÷ÀûÀÎ ºñ·á¿¡´Â ÀÌ·¯ÇÑ Áú¼ÒµéÀ» ´Ù·® ÇÔÀ¯ÇÏ°í ÀÖ´Ù.
ºñ·á¿¡ ÀÖ´Â nitric nitrogen °ú ammonia nitrogen ÀÇ ÇÔ·® ºÐ¼®
ÀÌ ¹æ¹ýÀº Devarda¡¯s alloy ¸¦ ÀÌ¿ëÇÏ¿© »ùÇÃÀ» ȯ¿ø½ÃÄÑ Áú»ê¿°°ú ¾Ï¸ð´Ï¾Æ¼º Áú¼ÒÀÇ ¾çÀ» ÃøÁ¤ÇÏ´Â °ÍÀÌ´Ù.
Áú»ê¿° À̿°ú Devarda¡¯s alloy ¿ë¾×À» sodium hydroxide ¿ë¾×°ú ¼¯°Ô µÇ¸é ¾Ï¸ð´Ï¾Æ ±âü°¡ ¹ß»ýÇÑ´Ù.
ÀÌ ¹æ¹ýÀº °ÅÀÇ ¸ðµç ÇüÅÂÀÇ Áú¼Ò ºñ·á¿¡ Àû¿ëÇÒ ¼ö ÀÖ´Ù.
Samples
Two samples of ammonium nitrate fertilizer have been tested :
- Fertilizer 1 expected value : 34.69 %N
- Fertilizer 2 expected value : 26.79 %N
Reagents and equipment
- Magnetic stirrer
- Burette 50 ml, precision 0.1 ml
- Sodium Hydroxide 32 %
- Devarda Alloy, powder
- Sodium hydroxide 0.1 N
- Sulfuric acid 0.2 N
- Methyl red in ethanol, as indicator
Sample Preparation
300 - 350 mg ÀÇ »ùÇÃÀ» test tube ¿¡ ³Ö°í ´Ù½Ã ¿©±â¿¡ 1.5g ÀÇ Devarda¡¯s alloy powder ¸¦ ³Ö´Â´Ù.
Distillation and titration
¹°°ú NaOH ¸¦ ³Ö°í ´ÙÀ½ Á¶°ÇÀ¸·Î ½Ã·á¸¦ distillation ÇÑ´Ù.
- H2O: 10 ml
- NaOH: 50 ml
- Receiving solution: 0 ml
- Distillation time: 5 min
- Steam power: 80 %
- Pause: 12 minutes
distillation °øÁ¤ ¸¶Áö¸·¿¡ No automatic distillation residues discharge À¸·Î ¼³Á¤ÇÑ´Ù.
receiving solution À¸·Î¼ 250 ml ¿ë·®ÀÇ Erlenmeyer flask ¿¡ 0.2 N Ȳ»ê¿ë¾× 50ml ¿Í 4 - 5 ¹æ¿ïÀÇ methyl red Áö½Ã¾à ¿ë¾×À» ³Ö´Â´Ù.
titrant solution À¸·Î¼ 0.1 N NaOH ¸¦ 50 ml burette À» ÀÌ¿ëÇÏ¿© »ö±òÀÌ º¯ÇÒ ¶§ ±îÁö õõÈ÷ ÅõÀÔÇÑ´Ù.
Typical Results on Fertilizer samples
ÅõÀÔµÈ titration solution ÀÇ ¿ë·® (ml) ·Î ºÎÅÍ ´ÙÀ½ °ø½ÄÀ» ÀÌ¿ëÇÏ¿© Áú¼Ò ÇÔ·® (%N) À» °è»êÇÑ´Ù.
- V1: ml of the receiving solution (50 ml)
- N1: Normality of the receiving solution (0.2 N)
- V2: ml of NaOH dosed for titration of the sample
- N2: Normality of the NaOH solution (0.1 N)
- V1B : ml of the receiving solution for the blank (10 ml)
- V2B : ml of NaOH dosed for titration of the blank
- MN : Nitrogen molecular weight (14.007 g/mol)
- msample : sample quantity (mg)
ÀÌ °ø½Ä¿¡ ÀÇÇØ ±¸ÇÑ ºñ·á »ùÇÃÀÇ Áú¼ÒÇÔ·® (%N) Àº ´ÙÀ½ table °ú °°´Ù.
Conclusions
VELP »çÀÇ UDK 149 Distillation Unit À» ÀÌ¿ëÇÏ¿© Devarda Method ¹æ¹ý¿¡ µû¶ó ÃøÁ¤ÇÑ ºñ·áÀÇ Áú¼Ò ÇÔ·®Àº
¿¹»óÄ¡¿¡ Á¤È®È÷ ÀÏÄ¡ÇÏ¿´´Ù.
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