Potassium tetrakis borate

Reagents used to formulate the membranes are valinomycin, nonactin, dibenzo(18-crown-6), bis(2-ethylhexyl) sebacate, bis(l-butylpentyl) adipate, poly(vinyl chloride) (PVC) (high molecular weight), potassium tetrakis(4-chlorophenyl)borate, all from Fluka. The different components are dissolved in tetrahydrofuran (Fluka) to form a membrane cocktail. 

Prepare the cocktail for the potassium sensor membrane mixing in a 3mL glass vial the following substances 0.0025 g of valinomycin (ionophore), 0.075 g of poly(vinyl chloride) (PVC), 0.165g of bis(2-ethylhexyl)sebacate (plasticizer), 0.0015 g of potassium tetrakis(4-chlorophenyl)borate (ionic additive) and 1.5 mL of tetrahydrofuran (THF). Cover the vial and shake it well, preferably in an orbital shaker for 30 min in order to dissolve and to homogenize the mixture. The resultant cocktail will suffice to prepare 10 sensors. 

IWAO Integrated waveguide absorbance optode KtpCIPB Potassium tetrakis(4-chlorophenyl)borate L, l Path length (cm)... 

The membrane used to activate this potassium-selective IWAO [134] consists of a potassium bulk optode based on 0.5 wt % chromoionophore ETH 5294, 1.0 wt% ionophore valinomycin, 0.5 wt% ionic additive potassium tetrakis(4-chlorophenyl)borate (KtpClPB), 31.0 wt % polymer PVC, 67.5 wt % organic solvent and plasticizer bis(2-ethylhexyl)sebacate (DOS) [142], This commercially available optode not only acts as an example of the development of an enhanced ion-selective IWAO, but also serves to validate the previously remarked features, because results can be compared with the ones obtained with membranes of the same composition and thickness in a con-... 

Preparation of sodium Urushi/ISFET. A mixture of 5 wt. % of ETH 227, 45 wt. % of di-2-ethylhexylphthalate (DOP Kishida Chemical Co. Ltd.) containing 0.5 wt. % of potassium tetrakis(4-chlorophenyl)borate (Dojin Research Laboratories Co. Ltd.) and 50 wt. % of Urushi (Saito Urushi Co. Ltd.) was coated on the FET devices and then the resulting Na+ Urushi membranes were hardened for 10 days at 30 °C and 90% relative humidity. The thickness of the membrane was approximately 0.1 mm. The surface of the Urushi matrix membrane was lustrous, smooth and adhesive to the gate of the device. The hardening mechanisms were discussed in detail elsewhere (6). 

C. POTASSIUM TETRAKIS(l-PYRAZOLYL)BORATE— ALKALI METAL POLY(1-PYRAZOLYL)BORATES... 

Potassium tetrakis(l-pyrazolyl)borate is a white solid, m.p. 253-254°C. Its infrared spectrum is devoid of BH bands. This salt is quite soluble in dimethylformamide (DMF) and dimethyl sulfoxide but less so in water and alcohols. Stable 0.1 M aqueous solutions may be prepared and used as needed. 

To a stirred solution of 31.8 g. (0.1 mole) of potassium tetrakis(l-pyrazolyl)borate in 300 ml. of dimethylformamide is added rapidly 100 ml. of 0.5 M manganese(II) sulfate solution. A precipitate forms immediately. The mixture is stirred for 10 minutes at room temperature and is then diluted with 300 ml. of water and filtered. The white solid is washed with copious amounts of water, then with methanol, and, finally, with a small amount of ether. After air-drying, there is obtained 29-30 g. (94-98%) of white solid. 

Kappes et al. evaluated the potentiometric detection of acetylcholine and other neurotransmitters through capillary electrophoresis [209]. Experiments were performed on an in-house capillary electrophoresis instrument that made use of detection at a platinum wire, dip-coated in 3.4% potassium tetrakis (4-chlorophenyl) borate/64.4% o-nitrohenyl octyl ether/32.2% PVC in THF. The results were compared to those obtained using capillary electrophoresis with amperometric detection at a graphite electrode. Samples prepared in the capillary electrophoresis buffer were electrokinetically injected (7 s at 5 kV) into an untreated fused silica capillary (88 cm x 25 pm i.d.) and separated with 20mM tartaric acid adjusted to pH 3 with MgO as the running buffer. The system used an applied potential of 30 kV, and detection versus the capillary electrophoresis ground electrode. 

Cecchi, T., Pucciarelli, R, and Passamonti, P. Potassium tetrakis (IH-pyrazolyl)borate a mobile phase additive for improved chromatography of metal chelating analytes. J. Liq. Chromatogr. Rel. Technol. 1997, 20, 3329-3337. 

Liquid ion-exchanger microelectrode cocktail A 2.10 wt% Potassium tetrakis(4-chlorophenyl)borate 12.10 wt% Trioctylphosphine oxide... 

In this work, an ionophore-based solvent polymeric membrane is cast on top of the PEDOT PSS channel in order to obtain an ion-selective organic electrochemical transistor (IS-OECT). The polymeric membrane is composed of 2-nitrophenyl octyl ether (o-NPOE, 57.2% ww), poly(vinyl chloride) (PVC, 27.9% ww), V.. V.. V. . V -i( I i i( ycloli( xyl-3-oxapentanedianii(le (ETH 129, 9.6% ww) and potassium tetrakis(4-chlorophenyl)borate (KTpCIPB, 5.4% ww), where ETH 129 is a Ca2+-selective ionophore. The channel region of the transistor that is coated by the Ca2+-selective membrane is immersed in an aqueous solution containing 0.1 M KC1 as a background electrolyte and... 

Prepare the 5 x lO"" M titrant by vigorously boiling 0.025 g potassium tetrakis(4-chlorophenyl)borate (TCPB) in water, with continuous stirring, cooling and diluting to 100 ml. 

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