Blood alkali metals

Unlike the previously mentioned systems, compounds such as (191) and (192) show no tendency to yield 2 1 (L M) complexes. These compounds show much promise as analytical reagents for the alkali metals and, for instance, have been demonstrated to be suitable for the extraction and spectrophotometric determination of Na+ in human blood serum. 

Among potentiometric enzyme sensors, the urea enzyme electrode is the oldest (and the most important). The original version consisted of an enzyme layer immobilized in a polyacrylamide hydrophilic gel and fixed in a nylon netting attached to a Beckman 39137 glass electrode, sensitive to the alkali metal and NHj ions [19, 2A Because of the poor selectivity of this glass electrode, later versions contained a nonactin electrode [20,22] (cf. p. 187) and especially an ammonia gas probe [25] (cf. p. 72). This type of urea electrode is suitable for the determination of urea in blood and serum, at concentrations from 5 to 0.05 mM. Figure 8.2 shows the dependence of the electrode response... 

Toxicity Variable. The hydrides of phosphorus, arsenic, sulfur, selenium, tellurium and boron which are highly toxic, produce local irritation and destroy red blood cells. They are particularly dangerous because of their volatility and ease of entry into the body. The hydrides of the alkali metals, alkaline earths, aluminum, zirconium and titanium react with moisture to evolve hydrogen and leave behind the hydroxide of the metallic element. This hydroxide is usually caustic. See also sodium hydroxide... 

Lithium is an alkali metal in group lA and shares many properties with similar elements such as sodium and potassium. As a compound it is rapidly absorbed and reaches peak blood levels in approximately 1 to 3 hours (6 to 8 hours with sustained release preparations), with absorption being completed in approximately 8 hours. Unlike other psychotropics, it is not protein-bound and steady-state levels are usually achieved after 4 to 6 days on a fixed dose. Table 10-16 lists the pharmacokinetic properties of lithium, as well as those of the other two commonly used mood stabilizers, VPA and CBZ. 

Potassium [7440-09-7], K, is the third element in the alkali metal series. The name designation for the element is derived from potash, a potassium mineral the symbol from the German name kalium, which comes from the Arabic qili, a plant. The ashes of these plants (a/ qih) were the historical source of potash for preparing fertilizers (qv) or gun powder. Potassium ions, essential to plants and animals, play a key role in carbohydrate metabolism in plants. In animals, potassium ions promote glycolysis, lipolysis, tissue respiration, and the synthesis of proteins (qv) and acetylcholine. Potassium ions are also believed to function in regulating blood pressure. 

The importance of maintaining precise concentration gradients is highlighted by the severe effects of metabolic disorders involving alkali metal cations. For example, high sodium intake is linked intimately with the development of high blood pressure on the other hand, aged... 

Albumen.2—When an albumen solution was electrolyzed by Dumas and Prevost, under conditions similar to those used by Becquerel for blood, the alkali metal went to the negative pole, hydrogen was evolved, and acetic and phosphoric acids appeared > at the positive pole. The result of this is that the albumen is coagulated at the negative pole (by the alkali present), while at the positive pole the solution remains clear. 

Carbon monoxide is very toxic, rapidly giving a bright red complex with the hemoglobin of blood. Carbon monoxide reacts with alkali metals in liquid ammonia to give the alkali metal carbonyls these white solids contain the [OCCO]2 ion. 

The alkali metal ions are very important for the proper functioning of biological systems, such as nerves and muscles Na+ and K+ ions are present in all body cells and fluids. In human blood plasma the concentrations are... 

Macrocyclic reagents, such as chromogenic crown ethers of the type 14-crown-4 (extraction to 1,2-dichloroethane in the presence of picrate) were used for determination of Li [53]. The 14-crown-4 type derivatives have been applied for determination of Li in blood by a continuous FIA method [54,55]. The use of chromogenic reagents aza-12 (-13 or -14)-crown-4 has also been proposed [56,57]. The effect of substituents on the selectivity of separation of Li (and Na) by means of benzo-14-crown-4 and 13-crown-4 ethers was studied [58]. A review of chromogenic macrocyclic reagents used for determination of lithium (and other alkali metals) has been published [32]. 

Physiological.—The fact that the carbonates of Na and K are almost invariably found in the ash of animal tissues and fluids, is no evidence of their existence there in life, as the carbonates are produced by the incineration of the Na and K salts of organic acids. There is, however, excellent indirect proof of the existence of the alkaline carbonates in the blood, especially of the herbivora, in the urine of the herbivora at all times, and in that of the carnivora and oiiinivora, when food rich in -the salts of the organic acids, with alkali metals, is taken. The carbonates in the blood are both the mono- and disodic, and potas-sic and the carbonic acid in the plasma is held partially in simple solution, and partly in combination in the monometallic carbonates. 

The alkali metal whose ion is more concentrated in intracellular fluids as compared with blood plasma. 

One of the most common applications of atomic-emission spectroscopy is the determination of the alkali metals, particularly in the clinical laboratory. Blood-serum samples need only to be diluted with water (or an internal-standard solution) and aspirated. 

Quantitative analysis-. Flame photometry is used for the quantitative determination of alkali metals and alkaline-earth metals in blood, serum, and urine in clinical laboratories. It provides much simpler spectra than those found in other types of AES, but its sensitivity is much reduced. 

The method employed for sample pretreatment prior to IC analysis is dependent on the sample type and the particular analytes under study. The determination of alkali metals in liquid samples, such as blood, plasma, and urine, is usually straightforward and requires only that the sample be... 

The alkali metal ions play an important role in human physiology, however. Sodium and potassium ions are major components of blood plasma and intracellular fluid, respectively with average concentrations on the order of 0.1 M. These electrolytes serve as vital charge carriers in normal cellular function, and they are two of the principal ions involved in regulation of the heart... 

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