Reagent-based tests

Therefore, an alternative test method, such as heating at 80 °C for 2 h, an alkali modified Coomassie-dye assay (e.g. Boyes et al. 1997), or the more recently available reagent based test kits such as Proteotest or Prostab, could present an opportunity to decrease bentonite dose and reduce volume of wine occluded in bentonite lees if confirmed to predict more accurately haze formation in wine. If these alternative test methods could replace the current heat test method of 80 °C for 6 h, this would also reduce the amount of time and/or effort presently required by a winery s laboratory to conduct heat stability testing. 

To test our new signal reagent based on GZ-11 the detection system was applied to two competitive-format immunoassays. These two assays (for atrazine and clenbuterol) normally use chromogenic detection systems. While these colorimetric assays may be adequate for laboratory use, chemiluminescent detection offers potential advantages in sensitivity and on site screening applications [33],... 

The Sharpless reagent, i.e. Ti(OPr-i)4/TBHP/diethyl tartrate, has been tested in the asymmetric BV oxidation of mono and bicyclic butanones . Conversions are low in all cases and ee values range from moderate to good. The best result has been obtained with the most bulky bicyclic ketone of the series, oxidized to the corresponding lactone with ee values up to 75%, using (+)-diethyl tartrate as ligand (equation 79). The use of a modified Sharpless reagent, based on Ti-TADDOL catalyst , increased the reaction rates, but decreased the enantiomeric excesses . ... 

Attempts to develop new aggregate-based recipes for catalytic decontamination of areas tainted with phosphorus-based persistent chemicals continue to receive attention. Most of these studies employ a simulant phosphotriester, p-nitrophenyldiphenyl phosphate (PNPDPP), as a test substrate and examine the efficacy of each formulation developed. Moss et al. described a potent estero-lytic reagent based on 9-iodoso-10-phenanthroate in micellar media [10]. 

In the closed reflux spectrophotometric method (Standard Method 5220 D), a standardized colorimetric reagent, based on dichromate, is provided in a sealed vial. Test samples are added to the vial and heated to 150 °C for 2 h in an aluminum block with appropriate holes to accommodate the vials. After cooling, the... 

None of the baths were direetly suitable for our purpose while the baths based on HAUCI4 showed some seleetivity, the deposits were to thin and to rough. The gold layers obtained from Na3Au(S03)2 were denser and smoother, but not site selective. A series of alternative reducing reagents was tested with... 

Various laboratory tests have been used for many years to assess the risk of protein turbidity before bottling. These tests are based on the instability of proteins under various conditions at high temperatures, or in the presence of tannin, trichloroacetic acid, ethanol or reagents based on phosphomolybdic acid. These tests do not all produce the same results. Some of them overestimate the risk of casse during bottle aging. This may lead to the use of much higher doses of bentonite than would be strictly necessary to ensure the protein stability of the wine. 

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