Native stock solutions

Prepare stock solutions of each native analyte (nominally 0.2 mg mL 200 ppm) by dissolving reference material in aqueous methanol (1 1, v/v). The reference materials should be stored in a refrigerator and protected from light when not in use. 

From the stock solutions of the individual native analytes, prepare a mixed fortification solution at 50 pgmL in methanol. Take an aliquot of this solution and dilute with aqueous methanol (1 1, v/v) to obtain a 0.25 p.gmL solution that will be used for... 

Four complete data sets were collected, two from native crystals (Native 1 and Native2) and two from heavy atom derivatives (HgCh and ethylmercurithiosalicylate (EMTS)). Nativel was mounted directly from mother liquor (2.0M ammonium sulfate in O.IM Hepes buffer pH7.5), and Native2 was soaked in the stock solution (2.6M ammonium sulfate in O.IM Hepes buffer pH6.9) used for heavy atom soaks. The results of data collection are summarized in Table 1. 

Native Cassia angustifolia (CA) seed gum with 1 mL of PAC stock solution at highly acidic pH (pH = 2.5) has been shown to remove 35% Acid Sendula Red, 22% Direct Kahi Green, and 16% Reactive Remazol Brilliant Violet dyes [9] while at alkaline pH (pH = 10) under identical conditions, the decol-orization efficiency of CA is reported to be about 80%, 99%, and 45% for acid, direct and reactive dyes, respectively. CA acts as a good working substitute... 

The results of this situation can be readily foreseen. A requisition for a specific item is occasionally filled with an item which, at first glance, appears to be the one requested but, actually, was formulated for a different purpose and is either inadequate or dangerous to use for the intended purpose. A specific example of the hazards inherent in this situation may be found in the case of insecticide space spray composed of 1% DDT, 0.1% pyrethrins, or 2.5% thiocyanate in deodorized kerosene and 5% residual-effect DDT, both of which are issued in 5-gallon steel drums. Obviously, if a requisition for residual-effect DDT were to be filled with space spray, the application of the solution as a residual-effect compound w ould be of little or no value. Under some conditions, when stocks have been exposed to such adverse weather conditions that all gross identifying marks have been removed from the containers, the assumption has been made by the untrained native laborers that all unidentifiable cans of the same size contained the same material. Were it possible to have just one insecticide for all military purposes, such a situation could easily be avoided. 

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