Notes on Apparatus

Experience indicates that any delicate weighing operation or highly precise titration work (such as is necessary for the best salinity determinations) is unsuited to routine shipboard use. It is also very inconvenient to undertake the evaporation and fuming of solutions in most ship laboratories. The methods in this manual have been designed with these considerations in mind and, whenever possible, substances are determined by light absorptiometry. 

Each method will be found to have a section entitled Special Apparatus and Equipment. Under this heading we have listed all apparatus and equipment which is not in common use in most chemical laboratories. However, certain pieces of equipment that are frequently specified will be discussed now rather than in the body of the text. 

Throughout this manual the term extinction (symbol E) is employed. The extinction is defined as log 1 1 where and 1 are incident and transmitted light intensities, respectively. Spectrophotometers are calibrated directly in extinction units (also called optical density or absorbency). If the absorptiometer employed reads percentage transmission, T, calculate E as logio(100/r). The use of transmission values in absorptiometry is to be discouraged as they are rarely if ever simply related to the concentration of substance being measured. 

For reagent volumes ranging between 0.5 and 5 ml, automatic pipettes are useful and are stipulated in most of the methods. We have found a simple rubber-bulb t5rpe (e.g. that made by Frederick G. Keys Ltd.) quite satisfoctory provided that reagent volumes are not critical to more than about 5%, but this t3rpe of pipette is not recommended when the addition of a solution governs the final volume used in an absorptiometer. 

Filtration is used either to separate particulate matter in sea water fof analysis or to obtain a particle-free sample of water for the analysis of soluble material. Several types of filter have been recommended for marine work and continuous centrifugation at high speed can be surprisingly effective although it is generally inconvenient to manipulate. To replace paper filters, organic membrane filters and glass-fiber or silver-fiber filter papers are commonly employed. Vacuum may be controlled by one of the devices mentioned on p. 182. 

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Quartz tubes and uv lamp equipment as described in the notes on apparatus section. Temperatures should be kept below 70 C in the tubes. 

Fused silica tubes of 110-ml capacity and the irradiation equipment specified in the notes on apparatus section, and 130-ml capacity special polyethylene bottles as specified in II.2.I,C are required. 

The filtration gear has been discussed in the section notes on apparatus. 

Dunham, N.W. and Miya, T.S., A note on a simple apparatus for detecting neurological deficitin mice and rats, /. Am. Pharm. Assoc., 46, 208-209, 1957. 

After the apparatus had been perfected, hydrogen was the first gas to be investigated and, although the investigation of this gas has not been completed, it seemed that a preliminary note on the apparatus, together with the results so far obtained, would be of interest to those engaged in ionization potential and allied work. 

Capacio BR, Harris LW, Anderson DR et al. (1992) Use of the accelerating rotarod for assessment of motor performance decrement induced by potential anticonvulsant compounds in nerve agent poisoning. Drug Chem Toxicol 15 177-201 Dunham NW, Miya TS (1957) A note on a simple apparatus for detecting neurological deficit in mice and in rats. J Am Pharm Ass 46 208-209... 

Automatic instruments for SPPS and their use are discussed in Section 4.3.6. Apparatus for manual SPPS will be discussed here, along with notes on the use of the various items. 

Thomas, K.B. The early use of chloroform with some notes on certain apparatus designed for its delivery. Anaesthesia 1971,26 (3). 

The test is conducted by placing a lOOl" O.lg sample, which has been previously dried and sifted thru a screen with 1mm openings, on a steel rectangular anvil, of apparatus and then allowing the hammer to drop from a predetermined height. More detailed description of the test is given in Ref 8 Note The apparatus gros mouton was first described by Commission des Substances Explosives in MP 15, 216 (1909)... 

Sorensen, M.V. (2003). Further structures in the jaw apparatus of Limnognathia maerski (Micrognathozoa), with notes on the phylogeny of the Gnathifera. Journal of Morphology 255,131-145. 

Note on the Handling of Hydrazine. Hydrazine, alone or in solution, attacks rubber and cork rapidly. Apparatus should have ground-glass connections, if possible. Hydrazine does not cause such jdnts to freeze. ... 

It will be noted that for the pure components the agreement is good. In the intermediate composition range much lower foam densities were noted on the small-scale apparatus on which mass transfer was occurring. On the large-tray apparatus, without mass transfer, there was still, however, a significant change in foam density with composition. 

In preparations involving the use of aliphatic diazo compounds, due caution must be exercised in the transfer of the diazoalkane solution to subsequent reaction systems and in the isolation of the final product. Particular attention must also be paid to the disposal of byproducts, to the handling of residues in the reaction flasks, and to traces of diazo compounds in the apparatus. Extensive notes on safety and health considerations for handling of diazomethane are givn by Gutsche [6], Moore and Reed [24], and De Boer and Backer [25]. The recommendations made for diazomethane should be applied to all the diazoalkanes and related compounds. To be kept in mind are the... 

Sulphur. THE LASSAIGNE SODIUM TEST. The sodium fusion will have converted any sulphur present in the original compounds to sodium sulphide. Dissolve a few crystals of sodium nitroprusside, Na8[Fe(CN)5NO],zH20, in water, and add the solution to the third portion of the filtrate obtained from the sodium fusion. A brilliant purple coloration (resembling permanganate) indicates sulphur the coloration slowly fades on standing. Note, (i) Sodium nitroprusside is unstable in aqueous solution and therefore the solution should be freshly prepared on each occasion, (ii) This is a very delicate test for sulphides, and it is essential therefore that all apparatus, particularly test-tubes, should be quite clean. 

Hydrolysis. Place 2 ml. of the ester in a 50 ml. round-bottomed flask fitted with a reflux water-condenser, or use the reflux-distillation apparatus shown in Fig. 38, p. 63. Add about 20 ml. of 10% aqueous NaOH solution, and some fragments of unglazed porcelain, and reflux gently for 20-30 minutes. (Note that methyl oxalate is hydrolysed rapidly by water alone. Phenyl esters on the other hand hydrolyse comparatively slowly even with hot NaOH solution, and should be heated... 

In compiling this book, the author has drawn freely from all sources of information available to him—research notes, original memoirs in scientific journals, reference works on organic chemistry, the numerous text books on practical organic chemistry, and pamphlets of manufac turers of specialised apparatus. Whilst individual acknowledgement cannot obviously be made—in many cases the original source has been lost track of—it is a duty and a pleasure to place on record the debt the writer owes to all these sources. Mention must, however, be made of Organic Syntheses, to which the reader is referred for further details of many of the preparations described in the text. 

Note. 3. All glassware of the distillation apparatus must be rinsed before use with a dilute solution of triethylamine Or another volatile amine in diethyl ether. Traces of acid on the glass walls may cause isomerization to H2C=CH-C(OCH3)=C(CH3)(OC2H5). 

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