BackgroundHigh nitrogen containing fertilizers may contain more than one source of nitrogen: Urea N Ammonium nitrate Ammonia in any combination 1 of organic matter* METHODS • BS EN 15750:2009 Fertilizers. ammoniacal an !rea nitrogen "y t#o ifferent met$o s • BS EN 15750 specifies two different methods (Methods A and B) for the determination of the total nitrogen content in fertilizers Method A specifies the titrimetric method after distillation according to BS !S" 5#15$1%&' Method B specifies a method () red*ction of nitrate with iron and tin(!!)+ chloride 2 . Determination of total nitrogen in fertilizers containing nitrogen only as nitric.Methods ISO 5315:19 ! "he metho# consists in re#ucing of nitrate to ammonia by chromium $o%#er in aci# me#ium& con'erting of organic an# urea nitrogen into ammonium sulfate by #igestion %ith concentrate# sulfuric aci# in the $resence of a catalyst& #istilling of the ammonia from an al(aline solution an# absorbing in an e)cess of stan#ar# 'olumetric so#ium hy#ro)i#e solution* "he metho# is not recommen#e# for materials containing more than + . +l-.0. 0! "a#$ eno%&h to make the sol%tion 10th normal and s%fficient Devarda's allo( )*%.Methods Cyanamid & Nitrate Mixtures-Davisson-Parsons The sample is placed in 800 cc Kjeldhal flask. Faithfull Determination of total nitrogen in presence of nitrate and organic N eagents: !alicylic acid !e po"der #$% sulfuric acid &n dust Apparatus: '(eldhal 3 .T. .. is added to red%ce all the nitrate nitro&en Methods in Agricultural Chemical Analysis: a practical handbook-N. -n. 100-200 cc D-water . /n granules. /n dust 0mpro1ed method for Nitrate free sample 2AOAC #3. 2 !"-$2 !"2 Cr Powder AOAC . /n powder 4 .AOAC Methods -et .++ !% .gO. digestion step followed by titration of the ammoniacal N AOAC Wet Methods AOAC 2 !"#$2 !"% &'ra(il) *aney Ni AOAC 2 !+.hemistry Principle: Destruction & reduction hydrolysis.$2 !"!. +" &-.go.++). . 9+ */0 Copper sulfate pentahydrate • AOA. 9+/*/3 *aney catalyst powder • AOA. 90/*/3 4gO • AOA.AOA.01 Hg AOAC 930.02 Hg AOAC 935.01 Devarda’s alloy AOAC 930. 90/*/5 5ormaldehyde titration 1for ammonium nitrate 2 sulfate3 • AOAC 920.05 Fe sulfate-Zn Soda AOAC 892.01 Hg 5 . 4 &m S!lfate • Fertilizer sam0les are li5!i *e6ce0t &m S!lfateO H H N N N O N H NH2 TKI AOAC MODIFIED METHOD 6 . &mmoni!m %$ios!lfate.T') A*AC M*D+F+CAT+*N! %$e mo ifications are for &'&( #et met$o s • )e !se )et *+. 3&N..el $al.et$o • )e analyses /5 sam0les 0er mont$ on t$e a1erage • )e analyze mostly !rea2formal e$y e con ensate 0ro !cts. 0. N(929 *29. #a-ing the method sa"er and more economical& 7 of Sam0les &nalyze (!0ric S!lfate & Sam0le &mmoni!m S!lfate *9eference St .*21.0.TKI AOAC Modified Method The Goals Kjeldhal Catalyst – Eliminating catalyst in Total Kjeldhal Digestion Procedure: AOAC (1 th edition! O""icial #ethod $%%&'( )itrogen (Total! in *ertili+ers.0/ < 0.1/ 25. N%9?SE9%2+@ *5. #a-ing the method more sa"e .:5 11.1= >0. N%9?SE9%2+S *15.0.00 < 0. N&mmoni!m t$ios!lfate *12.1: 1/.9/ 7 .1/ 29.'AENE2BA3S *29.09 5.20 1/.0/ 2=.0= e No 15 > 2 19 2 1: 5 1 10 1 21.y eliminating the ha+ardous metal salts (/gO0 1inc granules0 1inc dust!.0: 29.>7 2 2 5.5.1> < 0. N3ran2>2 *222 2/.01 2:.1:.25 < 0.97 < 0.90 < 0.0> < 0.0: 2=.:= < 0. N8es 21.15 25.12 < 0. N%9?SE9%2NB *2=.92 < 0.11 < 0.5. NF'9.00 2:.>/ 22.19 29..2> < 0. NN2S39E *2:.0.15 < 0. N%9?SE9%2(B *2=.91 < 0.0. "he results sho% that using the %et metho# %ith the aforementione# $ro#ucts #oes not nee# the metal salts use* "his com$arison sho%e# be e)ten#e# to other fertilizers to establishe# a generality* "his stu#y is only for -et .hemistry 145el#hal3 metho# recommen#e# by I6A 7as %ell .ombustion 8etho# 1AOA. 993*133 recommen#e# by I6A9* 8 .