Whole blood arsenic

A. Specific leveis. Urine and whole-blood arsenic levels may be elevated, but are rarely available in time to assist with prompt diagnosis and management. Whole-blood arsenic concentrations in patients with severe arsine poisoning have ranged from several hundred to several thousand micrograms per liter. 

Nixon DE, Moyer TP. Routine clinical determination of lead, arsenic, cadmium, mercury, and thaUium in urine and whole blood by inductively coupled plasma mass spectrometry Spectrochim Acta 1996 51B ... 

The first requirement can be easily fulfilled by the preconcentration of the analyte before the analysis. Preconcentration has been applied to sample preparation for flame atomic absorption (25) and, more recently, for ICP (79,80) spectroscopy. However, preconcentration is not completely satisfactory, because of the increased analysis time (which may be critical in clinical analysis) and the increased chance of contamination or sample loss. Most important, however, a larger initial sample size is necessary. The apparent solution is a more sensitive technique. Table 2 lists concentrations of various metals in whole blood or serum (81,82) in comparison to limits of detection for the various atomic spectroscopy techniques. In many cases, especially for the toxic heavy metals, only flameless atomic absorption using a graphite furnace can provide the necessary sensitivity and accommodate a sample of only a few microliters (Table 1). The determination of therapeutic gold in urine and serum (83,84), chromium in serum (85), skin (86) and liver (87), copper in semen (88), arsenic in urine (89), manganese in animal tissues (90), and lead in blood (91) are but a few examples in analyses which have utilized the flameless atomic absorption technique. 

A similar procedure, evaluated for the determination of selenium in body fluids by hydride / S, has been successfully used for arsenic as well. The flasks are the same as already described above with a long neck and 40 mL volume. However, flasks of similar design (e.g. Kjeldahl flasks) may be used as well. The procedure is as follows. 0.5 mL serum, whole blood or urine is placed into the digestion flasks. If necessary a sample volume of 1.0 ml may be also used. After this 1 mL of nitric acid (65% w/v) is added, the digestion flask placed into the aluminium heating block, and the block slowly heated to 140 °C. This temperature is maintained for 25 min and then cooled to room temperature. 0.5 mL (96% w/v) sulphuric and 0.2 mL (70% w/v) perchloric acid is added to the cool solution. The subsequent programme consists of slowly heating (approx. 15 min) to... 

NIOSH considers Lead to mean metallic lead, lead oxides, and lead salts (including organic salts such as lead soaps but excluding lead arsenate). The NIOSH REL for lead (8-hour TWA) is 0.050 mg/m air concentrations should be maintained so that worker blood lead remains less than 0.060 mg Pb/100 g of whole blood. 

After initial contradictory reports it is now established that arsenic can cross the blood-brain barrier and produces alternations in whole rat brain biogenic amines levels in animals chronically exposed to arsenite (Tripathi et al, 1997). The neurological effects are many and varied. Usually, peripheral neuropathy, sensory neuropathy (Hafeman et al, 2005), and encephalopathy are the initial complaints associated with acute arsenic poisoning. Acute exposure to arsenic in humans has been shown to result in problems of memory, difficulties in concentration, mental confusion, and anxiety (Hall, 2002 Rodriguez et al, 2003). Other neurological symptoms arising due to arsenic are primarily those of a peripheral sensory neuritis, predominantly numbness, severe paresthesia of the distal portion of the extremities, diminished sense of touch, pain, heat and cold, and symmetrically reduced muscle power (Menkes, 1997). 

P) Rats, The rat differs from other species in the whole-body retention, excretion, and distribution of iAs and its metabolites. In an early study, CouLSON and associates (1935) reported that rats excreted As derived from ingestion of shrimp faster than iAs which was added to the diet. Hunter and coworkers (1942) noted that the erythrocyte was the major depot for As following administration of iAs. Subsequent studies have confirmed the high accumulation and retention of As in the rat erythrocyte. In a comparison among species 48 h after intramuscular administration of sodium p" As ] arsenate, Lanz and coworkers (1950) found that the blood compartment of the rat accounted for nearly 45% of the administered dose of " As. In contrast, the blood compartment in cat accounted for 5.6% of the administered dose in dog, 0.1% in rabbit, 0.27%, in guinea pig, 0.25% in chicken, 0.19% and in mouse, 0.07%. 

---