Syringe-Pump Injection Method

Simulant vapors released into the test chamber are stirred with fans to produce a uniform challenge. The feed is monitored with proper analytical devices and data acquisition system. This system has been employed to generate a high volume of vapor in a large chamber for testing the protection efficiency of unhardened collective protection shelters. These shelters typically use filtered air to overpressurize the inside of the shelter to preclude infiltration of unwanted vapors. 

A variation of this method is to inject liquids with low boiling points directly into process streams by virtue of their own head pressure. Cyanogen chloride (CICN), for example, is frequently used to test developmental and fielded filtration 

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One of the widely used methods to qualitatively assess the matrix effect consists of post-column addition of analytes to the LC-eluent flowing from the column to the ESI interface of the mass spectrometer (Figure 13-11) [35]. Briefly, an analyte and the internal standard (IS) dissolved in the same EC eluent are infused (e.g., flow rate lOpL/min) using a syringe pump, through a tee-mixer, located between the column eluent (e.g., flow rate 200pL/min) and the ESI interface of the mass spectrometer. An extract (using LEE or SPE) or supernatant (if PPT is used) from an analyte-free matrix, such as blank or control plasma, is injected via the autosampler, while the test article and the internal standard are introduced, post-column, to the MS ionization... 

Drugs may require i.v. administration as continuous infusions or at intervals (q4h, q6h, ql2h, etc.). Manual methods require the administration of the drug into the i.v. system at an injection site (Y-site, T-connector, stopcock, etc.), added to the i.v. solution in a mixing chamber, or added to an i.v. bag to be administered via gravity. A syringe pump or another mechanical device may be used for drug administration. 

Caprioli and Lin first described this method for the characterization of penicillin G in 1990 [19]. A diagram of the microdialysis/cfFAB experimental setup used is shown in Fig. 8. Dialysate was allowed to collect in a 20- dL sampling loop via syringe pump. After collection, the injection valve was switched and a high-performance liquid chromatography pump was used to deliver the microdialysis sample to the mass spectrometer. Mass spectra of penicillin from both a standard and an in vivo microdialysis sample (shown in Fig. 9) compare well. 

Flash evaporation is another liquid vaporisation method as shown in Figure 3.6. By using a micropump (e.g. syringe pump, peristaltic pump), the amount of liquid can be accurately metered. When the liquid precursor is injected into the heat exchanger, it is immediately vaporised into gas, which in turn is introduced into the... 

In this system, liquid sample is introduced in to a stream containing reagents are transported through flexible plastic tubings by the action of a deliver pump such as peristaltic, HPLC, and syringe pump. Homogeneous flow injection (FI) methods with different detection system are described below. 

Only two flow analysis methods have been published for multianalyte determination including cyclamate as analyte. Both methods determine cyclamate with other artificial sweeteners. One of them used stabilized systems of filter-supported BLMs in a FIA manifold [72], and the other is based on CE with contactless conductivity detection employing a sequential injection manifold based on a syringe pump [77]. 

One factor in the reduction of healthcare expenditure is home medical care, which involves adaptations of the methods of care. These uses dictate particular requirements for sterility, safety, reliability, weight and facility of use. Plastics can bring solutions in the fields of single-use products, unbreakable equipment and weight reduction, for example, in the syringes, tubes and pumps for drug injections and apparatus for ambulatory dialysis. 

The stop-flow technique is the simplest and least expensive method of injection. The flow of the mobile phase is first stopped, either by turning an on—off valve in the line before the column (with constant-pressure systems), or by stopping the pump (with constant-flow systems). The column then returns rapidly to atmospheric pressure, and the sample can be injected directly on to the column with a normal low-pressure syringe. 

On column. One on-column sample application method involves stop-flow techniques. In this instance, the pump is stopped and isolated by a three-way valve from the column, the sample is then loaded via a syringe through an injection port which does not contain a septum. The pump is then restarted, the flow restored by switching the valve, and the sample is rapidly flushed onto the column. There is no apparent loss in efficiency but inaccuracies in retention measurement occur due to the finite time required for flow to be established and therefore this technique is redundant. 

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