High throughput mechanochemistry: application to parallel synthesis of benzoxazines.

We describe herein an unprecedented mechanochemical "parallel synthesis" of 3,4-dihydro-2H-benzo[e][1,3]oxazine derivatives via a one pot three component reaction. The new milling system uses a multiposition jar (variable sizes are possible), allowing for the processing of up to 12 samples simultaneously, leading to the formation of a fungicide and a building block for polymer preparation with higher throughput compared to standard milling devices.

Cocrystallization via planetary milling: enhancing throughput of solid-state screening methods.

The application of a novel modified planetary mill, with the capacity to process 48 samples in parallel, to the rapid screening of pharmaceutical cocrystals via grinding is demonstrated for carbamazepine/saccharin, caffeine/oxalic acid, and caffeine/maleic acid cocrystals. Milling is performed directly in standard glass vials therefore no vessel decontamination is needed or sample loss occurs. Furthermore, successive sample processing can be employed without the need for additional material, making the system suitable for screening compounds of limited availability.

Use of masking agents in the determination of lead in tap water by flame atomic absorption spectrometry with flow injection pre-concentration.

The selectivity of immobilised 8-hydroxyquinoline for lead is shown to be improved by the use of masking agents during pre-concentration, prior to determination by flame atomic absorption spectrometry. Interference by iron, copper, aluminium and zinc is suppressed by including triethanolamine, thiourea, fluoride, acetylacetone or cyanide in the buffer as masking agents. Species such as iron or copper can completely prevent the pre-concentration of lead.

Design and operation of an autosampler controlled flow-injection preconcentration system for lead determination by flame atomic absorption spectrometry.

Flow-injection manifolds are described which allow the preconcentration of lead for flame atomic absorption determinations, using columns contained within the sample loop of an injection valve. An interface was designed which allowed the valves and pump in the system to be controlled by an autosampler which enabled precise timing of preconcentration and elution steps. The effects of sample flow rate, buffer pH and buffer type for preconcentration and eluent concentration and flow rate were investigated in order to obtain optimum performance of the system.