Mini-Pump Model

A mini pump (model 396-31 Milton Roy instrument or equivalent)... 

Drug solutions and implantation of osmotic mini-pumps Physostigmine hemisulphate and procyclidine hydrochlorid were obtained from Sigma (St.Louis, U.S.A.), scopolamine hydrobromid from Merck (Darmstadt, Germany), atropine sulphate was obtained from ACF (Amsterdam, The Netherlands), and diazepam from Roche (The Netherlands). HI-6 was made available by the Defence Research Establishment, Suffield, Canada. Soman (O-pinacolyl methylphosphonofluoridate) was synthesised at TNO. Alzet Osmotic Mini-pumps with a constant delivery rate of 0.55 pl/hr (Model 2002, Alza Corp., Palo Alto, USA) were used to deliver PYR, PHY and SCO. The vehicle consisted of 20% propylene glycol, 10% ethanol and 70% water. The pumps were implanted subcutaneously under isoflurane/02 inhalation anesthesia. 

In the DuPont 848 liquid chromatograph, a special Haskel mini-pump is used, derived from the Haskel Model M. The volume of the cylinder is small (about 2 ml). In the original Haskel Model M pump, the return of the piston is actuated by an air selector valve and a spring, so that the liquid pressure is not constant because the gas piston must compress the spring during its forward stroke. In the modified pump, the spring is replaced with a small counter-pressure. The main characteristics of commercial pneumatic amplifier pumps are summarized in Table I. 

Laboratory Data Control modular liquid chromatograph equipped with a 254 nm UV monitor (Model 1285) together with two MUton Roy mini pumps equipped with a pulse dampener (LDC, Model 709)... 

All of the following components were used interchangeably. Pumps Model 396 Mini Pump (Laboratory Data Control) Model 6000 A Chromatographic Pump (Waters Assoc.)... 

Figure 1. The manifold (top) for the determination of phosphate hy FIA. Key P, the pump (Gilson Mini Puls) IV, injection valve (Rheodyne Model 50) D, LED photometer (24) with an IR LED (880-nm maximum emission) and R, recorder. Typical results for a series of standards are shown (hottorn).

LC Analyses, LC analyses were performed by using a Waters 600 pump equipped with a Rheodyne Model 7725i manual injector (50 pL loop) and a Waters Model 991 photodiode array detection system. Chromatographic separation was achieved on a YMC Pack PolymerCtS (YMC Inc. Wilmington, NC) column with a OPTI-SOLV mini filter (Optimise Technologies Inc., Portland, OR). The linear gradient was 60% H2O (solvent A)/40% acetonitrile (solvent B) which was held for 10 min, then increased by 8% acetonitrile/min to 20% H2O/80% acetonitrile, and held for 15 min. The flow rate was 0.8 mL/min. 

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