JPH056660B2 - - Google Patents
Info
- Publication number
- JPH056660B2 JPH056660B2 JP24800583A JP24800583A JPH056660B2 JP H056660 B2 JPH056660 B2 JP H056660B2 JP 24800583 A JP24800583 A JP 24800583A JP 24800583 A JP24800583 A JP 24800583A JP H056660 B2 JPH056660 B2 JP H056660B2
- Authority
- JP
- Japan
- Prior art keywords
- electrolytic solution
- karl fischer
- group
- coulometric titration
- sulfur dioxide
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 239000008151 electrolyte solution Substances 0.000 claims description 37
- RAHZWNYVWXNFOC-UHFFFAOYSA-N Sulphur dioxide Chemical compound O=S=O RAHZWNYVWXNFOC-UHFFFAOYSA-N 0.000 claims description 32
- 150000001412 amines Chemical class 0.000 claims description 31
- 238000005443 coulometric titration Methods 0.000 claims description 19
- 239000003792 electrolyte Substances 0.000 claims description 12
- ZCYVEMRRCGMTRW-UHFFFAOYSA-N 7553-56-2 Chemical compound [I] ZCYVEMRRCGMTRW-UHFFFAOYSA-N 0.000 claims description 11
- 229910052740 iodine Inorganic materials 0.000 claims description 11
- 239000011630 iodine Substances 0.000 claims description 11
- 125000000217 alkyl group Chemical group 0.000 claims description 9
- 125000004435 hydrogen atom Chemical group [H]* 0.000 claims description 8
- XMBWDFGMSWQBCA-UHFFFAOYSA-N hydrogen iodide Chemical compound I XMBWDFGMSWQBCA-UHFFFAOYSA-N 0.000 claims description 7
- 125000004076 pyridyl group Chemical group 0.000 claims description 3
- 125000000719 pyrrolidinyl group Chemical group 0.000 claims description 3
- JUJWROOIHBZHMG-UHFFFAOYSA-N Pyridine Chemical compound C1=CC=NC=C1 JUJWROOIHBZHMG-UHFFFAOYSA-N 0.000 description 18
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 15
- 238000005259 measurement Methods 0.000 description 13
- HEDRZPFGACZZDS-UHFFFAOYSA-N Chloroform Chemical compound ClC(Cl)Cl HEDRZPFGACZZDS-UHFFFAOYSA-N 0.000 description 11
- VHYFNPMBLIVWCW-UHFFFAOYSA-N 4-Dimethylaminopyridine Chemical compound CN(C)C1=CC=NC=C1 VHYFNPMBLIVWCW-UHFFFAOYSA-N 0.000 description 10
- 238000006243 chemical reaction Methods 0.000 description 10
- UMJSCPRVCHMLSP-UHFFFAOYSA-N pyridine Natural products COC1=CC=CN=C1 UMJSCPRVCHMLSP-UHFFFAOYSA-N 0.000 description 9
- 230000000052 comparative effect Effects 0.000 description 6
- RAXXELZNTBOGNW-UHFFFAOYSA-N imidazole Natural products C1=CNC=N1 RAXXELZNTBOGNW-UHFFFAOYSA-N 0.000 description 6
- NLKNQRATVPKPDG-UHFFFAOYSA-M potassium iodide Chemical compound [K+].[I-] NLKNQRATVPKPDG-UHFFFAOYSA-M 0.000 description 6
- FVAUCKIRQBBSSJ-UHFFFAOYSA-M sodium iodide Chemical compound [Na+].[I-] FVAUCKIRQBBSSJ-UHFFFAOYSA-M 0.000 description 6
- VZGDMQKNWNREIO-UHFFFAOYSA-N tetrachloromethane Chemical compound ClC(Cl)(Cl)Cl VZGDMQKNWNREIO-UHFFFAOYSA-N 0.000 description 6
- 238000004448 titration Methods 0.000 description 6
- UHPWYBATPHCMGD-UHFFFAOYSA-N 2-(3-pyridin-2-ylpropyl)pyridine Chemical compound C=1C=CC=NC=1CCCC1=CC=CC=N1 UHPWYBATPHCMGD-UHFFFAOYSA-N 0.000 description 5
- 229940021013 electrolyte solution Drugs 0.000 description 5
- 230000002123 temporal effect Effects 0.000 description 5
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 4
- -1 iodide ions Chemical class 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 3
- DNIAPMSPPWPWGF-UHFFFAOYSA-N Propylene glycol Chemical compound CC(O)CO DNIAPMSPPWPWGF-UHFFFAOYSA-N 0.000 description 3
- 125000003545 alkoxy group Chemical group 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- ARXJGSRGQADJSQ-UHFFFAOYSA-N 1-methoxypropan-2-ol Chemical compound COCC(C)O ARXJGSRGQADJSQ-UHFFFAOYSA-N 0.000 description 2
- OGNCVVRIKNGJHQ-UHFFFAOYSA-N 4-(3-pyridin-4-ylpropyl)pyridine Chemical compound C=1C=NC=CC=1CCCC1=CC=NC=C1 OGNCVVRIKNGJHQ-UHFFFAOYSA-N 0.000 description 2
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 2
- LRHPLDYGYMQRHN-UHFFFAOYSA-N N-Butanol Chemical compound CCCCO LRHPLDYGYMQRHN-UHFFFAOYSA-N 0.000 description 2
- DKGAVHZHDRPRBM-UHFFFAOYSA-N Tert-Butanol Chemical compound CC(C)(C)O DKGAVHZHDRPRBM-UHFFFAOYSA-N 0.000 description 2
- 230000005611 electricity Effects 0.000 description 2
- 150000008282 halocarbons Chemical class 0.000 description 2
- PNDPGZBMCMUPRI-UHFFFAOYSA-N iodine Chemical compound II PNDPGZBMCMUPRI-UHFFFAOYSA-N 0.000 description 2
- ZXEKIIBDNHEJCQ-UHFFFAOYSA-N isobutanol Chemical compound CC(C)CO ZXEKIIBDNHEJCQ-UHFFFAOYSA-N 0.000 description 2
- PSHKMPUSSFXUIA-UHFFFAOYSA-N n,n-dimethylpyridin-2-amine Chemical compound CN(C)C1=CC=CC=N1 PSHKMPUSSFXUIA-UHFFFAOYSA-N 0.000 description 2
- SVEUVITYHIHZQE-UHFFFAOYSA-N n-methylpyridin-2-amine Chemical compound CNC1=CC=CC=N1 SVEUVITYHIHZQE-UHFFFAOYSA-N 0.000 description 2
- 235000009518 sodium iodide Nutrition 0.000 description 2
- UOCLXMDMGBRAIB-UHFFFAOYSA-N 1,1,1-trichloroethane Chemical compound CC(Cl)(Cl)Cl UOCLXMDMGBRAIB-UHFFFAOYSA-N 0.000 description 1
- XNWFRZJHXBZDAG-UHFFFAOYSA-N 2-METHOXYETHANOL Chemical compound COCCO XNWFRZJHXBZDAG-UHFFFAOYSA-N 0.000 description 1
- OIALIKXMLIAOSN-UHFFFAOYSA-N 2-Propylpyridine Chemical compound CCCC1=CC=CC=N1 OIALIKXMLIAOSN-UHFFFAOYSA-N 0.000 description 1
- ZNQVEEAIQZEUHB-UHFFFAOYSA-N 2-ethoxyethanol Chemical compound CCOCCO ZNQVEEAIQZEUHB-UHFFFAOYSA-N 0.000 description 1
- RGUKYNXWOWSRET-UHFFFAOYSA-N 4-pyrrolidin-1-ylpyridine Chemical compound C1CCCN1C1=CC=NC=C1 RGUKYNXWOWSRET-UHFFFAOYSA-N 0.000 description 1
- 238000006641 Fischer synthesis reaction Methods 0.000 description 1
- 238000003109 Karl Fischer titration Methods 0.000 description 1
- CTQNGGLPUBDAKN-UHFFFAOYSA-N O-Xylene Chemical compound CC1=CC=CC=C1C CTQNGGLPUBDAKN-UHFFFAOYSA-N 0.000 description 1
- NINIDFKCEFEMDL-BKFZFHPZSA-N Sulfur-37 Chemical compound [37S] NINIDFKCEFEMDL-BKFZFHPZSA-N 0.000 description 1
- 150000001298 alcohols Chemical class 0.000 description 1
- 150000004945 aromatic hydrocarbons Chemical class 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000005868 electrolysis reaction Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 150000002391 heterocyclic compounds Chemical class 0.000 description 1
- 229940071870 hydroiodic acid Drugs 0.000 description 1
- 150000002484 inorganic compounds Chemical class 0.000 description 1
- 229910010272 inorganic material Inorganic materials 0.000 description 1
- GBMDVOWEEQVZKZ-UHFFFAOYSA-N methanol;hydrate Chemical compound O.OC GBMDVOWEEQVZKZ-UHFFFAOYSA-N 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- HMMPCBAWTWYFLR-UHFFFAOYSA-N n-pyridin-2-ylpyridin-2-amine Chemical compound C=1C=CC=NC=1NC1=CC=CC=N1 HMMPCBAWTWYFLR-UHFFFAOYSA-N 0.000 description 1
- 238000011017 operating method Methods 0.000 description 1
- 150000002894 organic compounds Chemical class 0.000 description 1
- 239000003209 petroleum derivative Substances 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 239000012086 standard solution Substances 0.000 description 1
- 239000008096 xylene Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N31/00—Investigating or analysing non-biological materials by the use of the chemical methods specified in the subgroup; Apparatus specially adapted for such methods
- G01N31/16—Investigating or analysing non-biological materials by the use of the chemical methods specified in the subgroup; Apparatus specially adapted for such methods using titration
- G01N31/168—Determining water content by using Karl Fischer reagent
Landscapes
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Molecular Biology (AREA)
- Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Pyridine Compounds (AREA)
Description
〔発明の利用分野〕
本発明はカールフイシヤー電量滴定用電解液に
係り、特に悪臭を有せず、性能が改善されたカー
ルフイシヤー電量滴定用電解液に関する。
〔従来技術〕
カールフイシヤー電量滴定法は公知であり、電
解液として通常主としてヨウ素、二酸化硫黄、ピ
リジン及びメタノールからなるものが用いられて
いる。実際に測定する時には、ヨウ素はヨウ素化
物イオンとして存在しており、試料が導入される
と同時に電解によりヨウ素を発生させカールフイ
シヤー反応を行なわせている。従つて、ヨウ素の
代りにヨウ素化カリウムやヨウ素化ナトリウムを
含有する電解液も用いられている。
カールフイシヤー電量滴定用電解液は、従来そ
の一成分として特異な臭いのあるピリジンを含ん
でいるため分析操作上不便をきたしてきた。従つ
てピリジン臭のない電解液が望まれており、ピリ
ジンの代りに種々の脂肪族アミンや複素環化合物
等を用いた電解液も最近になつて提案されている
（特開昭56−137250）。
一方、電解液としてはさらに、滴定時間を短縮
し得るという点でカールフイシヤー反応の反応速
度の高い電解液が望ましく、かつ装置の制御が容
易となり測定精度も向上させ得るという点では滴
定終点近くにおける電位変化が緩やかな電解液が
望ましい。しかるに前記した公知の電解液はこの
点において必ずしも充分なものではなかつた。
本出願人は、上述の要求を兼ね備えた電解液と
して、ピリジンの代りに、
一般式
（式中、R11，R12，R13，R14およびR15は水素
原子、アルキル基またはアルコキシル基であり、
そのうち少くとも１個はアルキル基またはアルコ
キシル基である）
で表わされる化合物、
及び、
一般式
（式中、R16，R17，R18，R19，R20，R21，R22
およびR23は水素原子、アルキル基またはアルコ
キシル基であり、ｎは１〜５の整数である）
で表わされる化合物、
からなる群から選ばれる少くとも１種のピリジン
系化合物を含有する電解液を見い出し、先に特許
出願を行なつた（特願昭57−234538（特開昭59−
122940号公報参照）、以下「先願」という）。先願
に係る電解液によれば、悪臭もなく高い反応速度
及び優れた滴定精度で、極めて有利にカールフイ
シヤー電量滴定を行なうことができる。
本発明者らは、先願と同様優れた効果を有する
カールフイシヤー電量滴定用電解液を提供すべく
さらに研究を重ねた結果、本発明に到達した。
〔発明の目的〕
本発明の目的は、ピリジン臭がなくまた反応速
度が高く、滴定終点近くにおける電位変化が緩や
かなカールフイシヤー電量滴定用電解液を提供す
ることにある。
〔発明の構成〕
この目的を達成するために、本発明における電
解液は、ヨウ素又はヨウ素化物、二酸化硫黄、ア
ルコール、必要に応じて加えられるクロロホルム
及び少なくとも２種の特定のアミンを主成分とす
るものであり、
ヨウ素又はヨウ素化物、二酸化硫黄及び及びア
ミンを含有してなるカールフイシヤー電量滴定用
電解液において、該アミンが、
(イ) 一般式
（式中、R1及びR2は水素原子、アルキル基、
ピリジル基又はピロリジニル基である）
で表わされるアミンの少くとも１種、
及び、
(ロ) 一般式
（式中、R3，R4，R5，R6，R7，R8，R9及び
R10は水素原子又はアルキル基であり、ｎは１〜
５の整数である）
で表わされるアミンの少くとも１種、
であることを特徴とするカールフイシヤー電量滴
定用電解液、
を要旨とするものである。
以下に本発明につき詳細に説明する。
本発明の電解液はその主成分として、まずヨウ
素又はヨウ素化物を含有する。ヨウ素化物として
はヨウ素化水素酸、ヨウ化カリウム、ヨウ化ナト
リウム等が好適である。電解液中のヨウ素又はヨ
ウ素化物の含有量はヨウ素換算で３〜0.1重量％、
好ましくは２〜0.3重量％が好適である。
二酸化硫黄の濃度は使用されるアミンの塩基性
度と共に反応速度に大きく影響し、塩基性度の小
さなアミンを用いた場合でも二酸化硫黄の濃度を
高くすることにより反応を速くすることができ
る。電解液中の二酸化硫黄の含有量は通常12〜
0.3重量％、好ましくは６〜1.2重量％とするのが
好適である。
アルコールとしてはメタノール、エタノール、
イソプロパノール、ｎ−ブタノール、イソブタノ
ール、tert−ブタノール等の低級脂肪族アルコー
ルが通常用いられるが、エチレングリコール、プ
ロピレングリコール、エチレングリコールモノメ
チルエーテル、エチレングリコールモノエチルエ
ーテル、１−メトキシ−２−プロパノール等も用
いることができる。電解液中のアルコールの濃度
は30〜70重量％が好ましい。
クロロホルムは各種の物質に対し大きな溶解力
を有しており、またカールフイシヤー反応を促進
する作用があるので電解液の一成分として用いら
れる。同様の目的で、クロロホルムの他に、１，
１，１−トリクロロエタン等のハロゲン化炭化水
素或いはキシレン等の芳香族炭化水素も用いるこ
とができる。電解液中のクロロホルム又は他のハ
ロゲン化炭化水素等の含有量は10〜50重量％が好
ましい。
本発明において使用されるアミンは下記の(イ)及
び(ロ)に示されるアミンである。
(イ) 一般式
（式中、R1及びR2は水素原子、アルキル基、
ピリジル基又はピロリジニル基である）
で表わされるアミンの少くとも１種。
(ロ) 一般式
（式中、R3，R4，R5，R6，R7，R8，R9及び
R10は水素原子又はアルキル基であり、ｎは１〜
５の整数である）
で表わされるアミンの少くとも１種。
即ち、本発明においては、これら(イ)及び(ロ)群のア
ミンは、いずれも１種ずつ用いても、或いは２種
以上を混合したものを用いてもよい。
(イ)群、即ち一般式（）で示されるアミンとし
ては、２−ジメチルアミノピリジン、４−ジメチ
ルアミノピリジン、２−メチルアミノピリジン、
２，2′−ジピリジルアミン、４−ピロリジノピリ
ジン等が挙げられる。また(ロ)群、即ち一般式
（）で示されるアミンとしては、１，３−ジ
（４−ピリジル）プロパン、１，３−ジ（２−ピ
リジル）プロパン等が挙げられる。特に(イ)群のア
ミンとしては４−ジメチルアミノピリジンが、(ロ)
群のアミンとしては１，３−ジ（２−ピリジル）
プロパンが好ましい。
電解液中のこれらアミンの濃度は前述のように
二酸化硫黄との割合が重要で、全アミン（(イ)及び
(ロ)の合計）と二酸化硫黄とのモル比で６：１から
0.3：１、好ましくは３：１から0.5：１が好適で
ある。
アミンとして(ロ)群のアミンだけでカールフイシ
ヤー電量滴定用電解液を調製すると、アミンの塩
基性がいくらか低いため、二酸化硫黄の刺激臭が
し、また反応速度も遅くなる。従つてこれらの欠
点を取り除くために、本発明においては、アミン
として(イ)群のアミンを併用する。このような二酸
化硫黄の刺激臭及び反応速度を一層改善するため
に、本発明においては、(イ)群のアミンの(ロ)群のア
ミンに対する割合は、モル比で0.3〜10、好まし
くは１〜３の範囲とするのが好適である。
本発明に係る電解液の組成は上記した通りであ
るが、試料に応じて電解液としての性能を改善す
るため上記の各成分以外に四塩化炭素等の他の成
分を若干含有させてもよい。
本発明に係る電解液を用いる水分定量は常法に
従つて行われる。即ち陽極室に本発明に係る電解
液を入れ陰極室に適当な陰極液を入れ通電して陽
極液中の水分を除去する。次いで陽極室に試料を
添加し再び通電して試料中の水分を滴定する。な
お陽極液の調製にヨウ素を用いた場合には試料測
定前にヨウ素の色が消えるまで水を添加する。ま
た陰極液としては例えばメタノール65重量％、四
塩化炭素20重量％、二酸化硫黄５重量％及び４−
ジメチルアミノピリジン10重量％の混合液が適当
である。
本発明に係る電解液は種々の物質、例えば有機
化合物、無機化合物、石油類、石化製品等の水分
の測定に用いることができる。
〔発明の実施例〕
以下に実施例により本発明をさらに具体的に説
明するが本発明はその要旨を超えない限り以下の
実施例に限定されるものではない。
実施例 １
４−ジメチルアミノピリジン8.8ｇ、１，３−
ジ（２−ピリジル）プロパン8.7ｇ、ヨウ素0.64
ｇ、二酸化硫黄5.1ｇ、及びクロロホルム37ｇを
メタノールで溶かし、100ml定容にする。このよ
うにして調製した電解液を市販のカールフイシヤ
ー電量滴定装置（デイジタル微量水分測定装置
CA−02型：三菱化成工業(株)製）の陽極室に入れ
る。陰極室にはメタノール65重量％、四塩化炭素
20重量％、二酸化硫黄５重量％及び４−ジメチル
アミノピリジン10重量％からなる混合液を入れ
る。しかる後上記電量滴定装置の操作法に従つ
て、水−メタノールの標準溶液（20mgH2Ｏ／ml）
を100μl注入し、H2Ｏ測定値及び測定所要時間を
求めた。結果を表１に示す。またその時の検出電
圧の経時変化を第１図に示す。
実施例 ２
４−ジメチルアミノピリジンのかわりに２−メ
チルアミノピリジン7.8ｇを、また１，３−ジ
（２−ピリジル）プロパンのかわりに１，３−ジ
（４−ピリジル）プロパン8.7ｇを用いたこと以外
は実施例１と同様にして電解液を調製し、H2Ｏ
測定値及び測定所用時間を求めた。結果を表１に
示す。またその時の検出電圧の経時変化を第１図
に示す。
比較例 １
アミンとしてピリジンを用いた市販の電解液
（商品名アクアミクロンＡ：三菱化成工業(株)製）
を用いたこと以外は実施例１と同様にしてH2Ｏ
測定値及び測定所要時間を求めた。結果を表１に
示す。またその時の検出電圧の経時変化を第１図
に示す。
比較例 ２
アミンとして１，３−ジ（２−ピリジル）プロ
パン19.8ｇを用いたこと以外は実施例１と同様に
して電解液を調製し、H2Ｏ測定値及び測定所用
時間を求めた。結果を表１に示す。またその時の
検出電圧の経時変化を第１図に示す。
比較例 ３
アミンとしてイミダゾールを用いた市販の電解
液（商品名ハイドラナール・クーロマートＡ：リ
ーデル・デ・ヘーン社（西ドイツ）製）を用いた
こと以外は実施例１と同様にしてH2Ｏ測定値及
び測定所要時間を求めた。結果を表１に示す。ま
たその時の検出電圧の経時変化を第１図に示す。
[Field of Application of the Invention] The present invention relates to an electrolytic solution for Karl Fischer coulometric titration, and particularly to an electrolytic solution for Karl Fischer titration that does not have a bad odor and has improved performance. [Prior Art] The Karl Fischer coulometric titration method is well known, and the electrolyte solution usually consists mainly of iodine, sulfur dioxide, pyridine and methanol. During actual measurements, iodine exists as iodide ions, and at the same time as the sample is introduced, iodine is generated by electrolysis to cause the Karlfischer reaction. Therefore, electrolytes containing potassium iodide or sodium iodide are also used instead of iodine. Electrolyte solutions for Karl Fischer coulometric titrations have conventionally contained pyridine, which has a peculiar odor, as one of its components, which has caused inconvenience in analytical operations. Therefore, an electrolytic solution without pyridine odor is desired, and electrolytic solutions using various aliphatic amines, heterocyclic compounds, etc. in place of pyridine have recently been proposed (Japanese Patent Laid-Open No. 137250/1982). . On the other hand, as an electrolytic solution, it is desirable to use an electrolytic solution that has a high reaction rate for the Karl Fischer reaction because it can shorten the titration time, and it is also desirable to use an electrolytic solution that is close to the titration end point because it makes it easier to control the device and improves measurement accuracy. An electrolytic solution with a gradual change in potential at is desirable. However, the above-mentioned known electrolytes were not necessarily sufficient in this respect. The applicant has proposed that, instead of pyridine, the general formula (In the formula, R 11 , R 12 , R 13 , R 14 and R 15 are hydrogen atoms, alkyl groups or alkoxyl groups,
At least one of which is an alkyl group or an alkoxyl group) and a compound represented by the general formula (In the formula, R 16 , R 17 , R 18 , R 19 , R 20 , R 21 , R 22
and R 23 is a hydrogen atom, an alkyl group, or an alkoxyl group, and n is an integer of 1 to 5). A patent application was filed earlier (Japanese Patent Application No. 57-234538 (Japanese Unexamined Patent Publication No. 59-1989)
(see Publication No. 122940), hereinafter referred to as the "prior application"). According to the electrolytic solution according to the prior application, Karl Fischer coulometric titration can be carried out very advantageously without any bad odor, at a high reaction rate, and with excellent titration accuracy. The present inventors have conducted further research in order to provide an electrolytic solution for Karl Fischer coulometric titration that has excellent effects similar to those of the previous application, and as a result, they have arrived at the present invention. [Object of the Invention] An object of the present invention is to provide an electrolytic solution for Karl Fischer coulometric titration that has no pyridine odor, has a high reaction rate, and has a gradual change in potential near the end point of titration. [Structure of the Invention] In order to achieve this object, the electrolytic solution in the present invention mainly contains iodine or an iodide, sulfur dioxide, alcohol, chloroform added as necessary, and at least two specific amines. In an electrolytic solution for Karl Fischer coulometric titration containing iodine or an iodide, sulfur dioxide, and an amine, the amine has the following general formula: (In the formula, R 1 and R 2 are hydrogen atoms, alkyl groups,
pyridyl group or pyrrolidinyl group); and (b) general formula (In the formula, R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 and
R 10 is a hydrogen atom or an alkyl group, and n is 1 to
An electrolytic solution for Karl Fischer coulometric titration, characterized in that the electrolyte is at least one kind of amine represented by: The present invention will be explained in detail below. The electrolytic solution of the present invention first contains iodine or an iodide as its main component. As the iodide, hydroiodic acid, potassium iodide, sodium iodide, etc. are suitable. The content of iodine or iodide in the electrolyte is 3 to 0.1% by weight in terms of iodine,
Preferably 2 to 0.3% by weight is suitable. The concentration of sulfur dioxide greatly influences the reaction rate together with the basicity of the amine used, and even when an amine with low basicity is used, the reaction can be accelerated by increasing the concentration of sulfur dioxide. The content of sulfur dioxide in the electrolyte is usually 12~
A suitable amount is 0.3% by weight, preferably 6-1.2% by weight. Alcohols include methanol, ethanol,
Lower aliphatic alcohols such as isopropanol, n-butanol, isobutanol, and tert-butanol are usually used, but ethylene glycol, propylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 1-methoxy-2-propanol, etc. are also used. Can be used. The concentration of alcohol in the electrolyte is preferably 30 to 70% by weight. Chloroform has a large dissolving power for various substances and also has the effect of promoting the Karlfischer reaction, so it is used as a component of the electrolyte. For the same purpose, in addition to chloroform, 1,
Halogenated hydrocarbons such as 1,1-trichloroethane or aromatic hydrocarbons such as xylene can also be used. The content of chloroform or other halogenated hydrocarbons in the electrolytic solution is preferably 10 to 50% by weight. The amines used in the present invention are shown in (a) and (b) below. (a) General formula (In the formula, R 1 and R 2 are hydrogen atoms, alkyl groups,
At least one amine represented by: pyridyl group or pyrrolidinyl group. (b) General formula (In the formula, R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 and
R 10 is a hydrogen atom or an alkyl group, and n is 1 to
at least one type of amine represented by: That is, in the present invention, the amines of groups (a) and (b) may be used singly or in a mixture of two or more. Group (a), ie, the amine represented by the general formula (), includes 2-dimethylaminopyridine, 4-dimethylaminopyridine, 2-methylaminopyridine,
Examples include 2,2'-dipyridylamine and 4-pyrrolidinopyridine. Examples of the (b) group, ie, the amine represented by the general formula (), include 1,3-di(4-pyridyl)propane, 1,3-di(2-pyridyl)propane, and the like. In particular, 4-dimethylaminopyridine is the amine of group (a), and (b)
The group of amines includes 1,3-di(2-pyridyl)
Propane is preferred. As mentioned above, the ratio of these amines to sulfur dioxide in the electrolyte is important;
The molar ratio of (sum of (b)) and sulfur dioxide is from 6:1.
0.3:1, preferably 3:1 to 0.5:1 is suitable. When an electrolyte for Karl Fischer coulometric titration is prepared using only the amines of group (B) as the amines, the basicity of the amines is somewhat low, resulting in a pungent odor of sulfur dioxide and a slow reaction rate. Therefore, in order to eliminate these drawbacks, in the present invention, amines of group (a) are used in combination as the amine. In order to further improve the irritating odor and reaction rate of sulfur dioxide, in the present invention, the molar ratio of the amines in group (a) to the amines in group (b) is 0.3 to 10, preferably 1. It is preferable to set it in the range of ~3. The composition of the electrolytic solution according to the present invention is as described above, but in addition to the above-mentioned components, a small amount of other components such as carbon tetrachloride may be included in order to improve the performance as an electrolytic solution depending on the sample. . Moisture determination using the electrolytic solution according to the present invention is carried out according to a conventional method. That is, an electrolytic solution according to the present invention is placed in the anode chamber, and a suitable catholyte is placed in the cathode chamber and electricity is applied to remove water in the anolyte. Next, a sample is added to the anode chamber and electricity is applied again to titrate the water content in the sample. Note that when iodine is used to prepare the anolyte, water is added until the color of iodine disappears before sample measurement. Further, as the catholyte, for example, 65% by weight of methanol, 20% by weight of carbon tetrachloride, 5% by weight of sulfur dioxide, and 4-
A 10% by weight mixture of dimethylaminopyridine is suitable. The electrolytic solution according to the present invention can be used to measure the moisture content of various substances, such as organic compounds, inorganic compounds, petroleum products, and petrochemical products. [Examples of the Invention] The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited to the following Examples unless the gist of the invention is exceeded. Example 1 8.8 g of 4-dimethylaminopyridine, 1,3-
Di(2-pyridyl)propane 8.7g, iodine 0.64
g, 5.1 g of sulfur dioxide, and 37 g of chloroform are dissolved in methanol to a constant volume of 100 ml. The electrolyte solution prepared in this way was measured using a commercially available Karl Fischer coulometric titration device (digital trace moisture measuring device).
Type CA-02: Place in the anode chamber manufactured by Mitsubishi Chemical Industries, Ltd. 65% methanol and carbon tetrachloride in the cathode chamber
A mixture of 20% by weight, 5% by weight of sulfur dioxide and 10% by weight of 4-dimethylaminopyridine is added. After that, according to the operating method of the coulometric titration device described above, a standard solution of water-methanol (20 mgH 2 O/ml) was added.
100 μl of the solution was injected, and the H 2 O measurement value and the time required for measurement were determined. The results are shown in Table 1. Further, FIG. 1 shows the temporal change in the detected voltage at that time. Example 2 7.8 g of 2-methylaminopyridine was used in place of 4-dimethylaminopyridine, and 8.7 g of 1,3-di(4-pyridyl)propane was used in place of 1,3-di(2-pyridyl)propane. An electrolytic solution was prepared in the same manner as in Example 1 except that H 2 O
Measured values and time required for measurement were determined. The results are shown in Table 1. Further, FIG. 1 shows the temporal change in the detected voltage at that time. Comparative Example 1 Commercially available electrolyte using pyridine as the amine (trade name Aquamicron A: manufactured by Mitsubishi Chemical Industries, Ltd.)
H 2 O
Measured values and time required for measurement were determined. The results are shown in Table 1. Further, FIG. 1 shows the temporal change in the detected voltage at that time. Comparative Example 2 An electrolytic solution was prepared in the same manner as in Example 1 except that 19.8 g of 1,3-di(2-pyridyl)propane was used as the amine, and the H 2 O measurement value and measurement time were determined. The results are shown in Table 1. Further, FIG. 1 shows the temporal change in the detected voltage at that time. Comparative Example 3 H 2 O measurement was carried out in the same manner as in Example 1, except that a commercially available electrolyte solution (trade name: Hydranal Coulomat A, manufactured by Riedel de Haene (West Germany)) using imidazole as the amine was used. The value and the time required for measurement were determined. The results are shown in Table 1. Further, FIG. 1 shows the temporal change in the detected voltage at that time.
以上詳述した如く、本発明のカールフイシヤー
電量滴定用電解液は、ピリジン臭等の悪臭や刺激
臭を有せず、また高い反応速度を有することから
測定時間が短くかつ滴定終点近くにおける電位変
化が緩やかであることから測定の制御も容易であ
る。従つて、本発明の電解液によれば短時間でか
つ高い精度で容易にカールフイシヤー電量滴定を
行なうことができ、滴定の作業環境も良好であ
る。
As described in detail above, the electrolyte solution for Karl Fischer coulometric titration of the present invention does not have a bad or irritating odor such as pyridine odor, and has a high reaction rate, so that the measurement time is short and the potential near the end point of titration is Since the change is gradual, the measurement can be easily controlled. Therefore, according to the electrolytic solution of the present invention, Karl Fischer coulometric titration can be easily performed in a short time and with high accuracy, and the working environment for titration is also favorable.
第１図は実施例１，２及び比較例１〜３におけ
る電量滴定の際の検出電圧の経時変化を示すグラ
フであり、実線は本発明の電解液（実施例１，
２）によるもの、破線は、ピリジン又は１，３−
ジ（２−ピリジルプロパン単独を用いた電解液
（比較例１，２）によるもの、一点鎖線はイミダ
ゾールを用いた電解液（比較例３）によるものを
示す。
FIG. 1 is a graph showing the change over time of the detected voltage during coulometric titration in Examples 1 and 2 and Comparative Examples 1 to 3, and the solid line is the electrolytic solution of the present invention (Example 1,
2), the broken line indicates pyridine or 1,3-
The electrolytic solution using di(2-pyridylpropane alone) (Comparative Examples 1 and 2) was used, and the dashed line indicates the electrolytic solution using imidazole (Comparative Example 3).
Claims (1)
ンを含有してなるカールフイシヤー電量滴定用電
解液において、該アミンが、 (イ) 一般式 （式中、R1及びR2は水素原子、アルキル基、
ピリジル基又はピロリジニル基である） で表わされるアミンの少くとも１種、 及び、 (ロ) 一般式 （式中、R3，R4，R5，R6，R7，R8，R9及び
R10は水素原子又はアルキル基であり、ｎは１〜
５の整数である） で表わされるアミンの少くとも１種、 であることを特徴とするカールフイシヤー電量滴
定用電解液。 ２ 電解液中の全アミンの二酸化硫黄に対するモ
ル比が６：１から0.3：１の範囲であることを特
徴とする特許請求の範囲第１項に記載のカールフ
イシヤー電量滴定用電解液。 ３ (イ)群のアミンの(ロ)群のアミンに対する割合が
モル比で0.3〜10であることを特徴とする特許請
求の範囲第１項又は第２項に記載のカールフイシ
ヤー電量滴定用電解液。 ４ 電解液中の二酸化硫黄の含有量が12〜0.3重
量％であることを特徴とする特許請求の範囲第１
項ないし第３項のいずれか１項に記載のカールフ
イシヤー電量滴定用電解液。[Scope of Claims] 1. An electrolytic solution for Karl Fischer coulometric titration containing iodine or an iodide, sulfur dioxide, and an amine, wherein the amine has the following general formula: (In the formula, R 1 and R 2 are hydrogen atoms, alkyl groups,
pyridyl group or pyrrolidinyl group); and (b) general formula (In the formula, R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 and
R 10 is a hydrogen atom or an alkyl group, and n is 1 to
An electrolytic solution for Karl Fischer coulometric titration, characterized in that it is at least one kind of amine represented by (an integer of 5). 2. The electrolytic solution for Karl Fischer coulometric titration according to claim 1, characterized in that the molar ratio of total amines to sulfur dioxide in the electrolytic solution is in the range of 6:1 to 0.3:1. 3. Karl Fischer coulometric titration according to claim 1 or 2, characterized in that the molar ratio of the amines of group (a) to the amines of group (b) is 0.3 to 10. Electrolyte. 4 Claim 1 characterized in that the content of sulfur dioxide in the electrolyte is 12 to 0.3% by weight
The electrolytic solution for Karl Fischer coulometric titration according to any one of Items 1 to 3.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24800583A JPS60140152A (en) | 1983-12-28 | 1983-12-28 | Electrolyte for karl fischer coulmetric titration |
| US06/674,589 US4720464A (en) | 1983-12-28 | 1984-11-26 | Electrolytes for Karl Fischer coulometric titration |
| GB08432166A GB2152676B (en) | 1983-12-28 | 1984-12-20 | Electrolytes for karl fisher coulometric titration |
| DE3447455A DE3447455C2 (en) | 1983-12-28 | 1984-12-27 | Electrolyte for coulometric Karl Fischer titration |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24800583A JPS60140152A (en) | 1983-12-28 | 1983-12-28 | Electrolyte for karl fischer coulmetric titration |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60140152A JPS60140152A (en) | 1985-07-25 |
| JPH056660B2 true JPH056660B2 (en) | 1993-01-27 |
Family
ID=17171771
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP24800583A Granted JPS60140152A (en) | 1983-12-28 | 1983-12-28 | Electrolyte for karl fischer coulmetric titration |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60140152A (en) |
-
1983
- 1983-12-28 JP JP24800583A patent/JPS60140152A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60140152A (en) | 1985-07-25 |
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