Determination Of Lead Content Research Articles

Determination of lead content in leaded gasolines

The authors describe a proposed combination method for TEL determination in which the TEL is decomposed by means of freshly liberated iodine, and the lead is determined by oscillographic polarography. It is proposed that TEL should be decomposed by successive action of HC1, KI, and KIO/sub 3/. The iodine released in the course of the reaction decomposes the TEL. The gasolines used for analysis contained different amounts of lead. The lead determination procedure is described, and the time required for analysis is about 30 minutes. The results obtained in the analysis, treated statistically, are presented in a table.

705—A simple, rapid and sensitive alternating current tast-polarographic method for lead determination in bones

A simple and reliable alternating current tast-polarographic method is described to determine lead concentration in bone. The bone samples are solubilized and oxidized with a HNO 3-HClO 4 mixture and after evaporating the acids the residue is dissolved in 20% citric acid used as a supporting electrolyte. The high inorganic salt concentrations from the bone matrix do not impede the polarographic measurement. Sensitivity: 2 p.p.m. lead in bone. Standard error: 6%. Reliability range: 2–1000 p.p.m.

Vulnerability to lead in protein-deprived suckling rats.

Most studies on lead toxicity in the suckling rat have been performed with doses leading to growth retardation. In a previous paper ( Sundstr öm et al. 1983), the effects of different lead doses on normal suckling rats were described. The dose of 10 mg/kg body weight daily given on days 1-15 pp produced minute hemorrhagic lesions on day 15 in the cerebellum, whereas rats given 5 mg/kg body weight daily lacked microscopically discernible pathologic changes in the brain. None of these groups exhibited growth retardation. To further elucidate the association between lead encephalopathy and malnutrition, lead was administered to protein-deprived suckling rats. Protein deprivation was achieved by a diet with 50% reduction of protein content. The mothers of the pups were fed this diet from 2 weeks before conception throughout the experiment. Experimental animals were injected i.p. with 5 mg or 10 mg lead nitrate/kg b.wt. daily. Littermates, injected with vehicle without lead nitrate served as controls. Protein-deprived rats without either treatment were "external" controls. Animals were killed at 10, 15, and 20 days age for determination of lead content in blood and brain and for light-microscopic examination. The protein-deprived rats given 10 mg/kg b.wt. daily were growth-retarded as compared to unexposed protein-deprived rats. The mortality was almost 100% at 15-20 days pp. At 15 days, the cerebellum of these rats showed abundant hemorrhages, and the cerebrum was also hemorrhagically discolored. Protein-deprived rats given 5 mg/kg b.wt. daily did not differ significantly from unexposed protein-deprived rats with regard to body weight gain.(ABSTRACT TRUNCATED AT 250 WORDS)

Indirect Atomic Absorption Spectrometric Assay for Epoxide Hydrolase

Abstract An indirect atomic absorption spectrometric assay for epoxide hydrolase was reported. The enzymatic product 1,2-diol was oxidized by an excess of potassium periodate, and the unconsumed periodate was preferrentially precipitated by lead periodate. The precipitate was acid digested followed by atomic absorption determination of lead in the resulting solution. Trans-stilbene oxide (TSO) induced rabbit and tilapia epoxide hydrolase activities by 350% and 210% at the 490 mg TSO/kg treatment while Aroclor 1254(AR) only slightly increased their activities at the 200 mg AR/kg treatment. The 1,2-epoxy-3,3,3-trichloropropane (TCPO) at 0.1 mM completely inhibited tilapia (control) and rabbit (490 mg TSO/kg) epoxide hydrolase activities.

Lead and Barium in Archaeological Roman Skeletons Measured by Nondestructive X-Ray Fluorescence Analysis

Lead is a non-essential toxic metal of considerable topicality. It is accumulated in the skeleton, which contains 90% of the total body burden.It is known that during the Roman period the intake of lead was high. The Romans used kitchen utensils made of lead and lead pipes for drinking water. The most important source of lead for people of the upper social classes was sapa, a compound added to wine to sweeten and perserve it.Using non-destructive X-ray fluorescence analysis, lead and barium concentrations of archaeological Roman bones have been measured. We have earlier used a similar technique to determine lead concentration in the human skeleton in vivo.

Lead determination in airborne particulate matter by proton activation analysis.

Proton activation analysis has been applied to determine lead concentrations in airborne particulate matter collected on filter papers. /sup 204/Bi radioactivity, produced by 40-50 MeV proton activation via /sup 206/Pb(p,3n), /sup 207/Pb(p,4n), /sup 208 /Pb(p,5n) reactions, is used to identify and measure trace amounts of lead. The 374-KeV gamma ray is usually used to identify lead; however, gamma rays above the annihilation radiation, as the 899 KeV, are sometimes more suitable. Counting times range from 5 to 50 min per sample. Under reasonable irradiation and counting conditions, and without chemical separations, sensitivities of less than 1 ng/cm/sup 2 / are currently obtained.

Lead content of human blood, hair, and deciduous teeth: correlation with environmental factors and growth.

Determination of lead content of deciduous teeth may provide a useful index to previous lead exposure.

Atomic Absorption Determination of Lead in Apples

Abstract Two studies have been conducted on the analysis of apples for lead by atomic absorption spectrophotometry using the official first action method, 25.B01–25.B05. Sixteen laboratories participated in each study. Recoveries ranged from 92.6 to 110% (101.6% average) in the first study. A second study, in which procedural modifications were made, showed recoveries ranging from 91.2 to 109.7%, with an average of 100.0%. Coefficients of variation for the first and second studies were 5.19 and 4.94%, respectively. On the basis of the second study, procedural modifications have been incorporated into the 12th Edition of Official Methods of Analysis.

Modified Delves Cup Atomic Absorption Determination of Lead in Blood

Abstract A modification of the Delves atomic absorption micro method for blood lead determinations is presented. The principal differences between the present modification and the original Delves method are the improvement in hardware to overcome problems in reproducibility and a char method to essentially eliminate the smoke peak which normally causes serious interference. The method has been applied to several different types of blood samples with excellent results.

The analysis of lead in commercial gasolines from the Ottawa area

An accurate and simple method using atomic absorption spectroscopy has been developed to determine lead concentrations found in commercial gasolines. A survey of 48 gasoline samples collected from the Ottawa area showed average concentrations of 775 and 666 μg Pb/ml for premium and regular grades, respectively.

Atomic absorption determination of lead in blood and urine in the presence of EDTA.

Abstract An atomic absorption method for the determination of lead in blood and urine is described, which can be applied without prior acid digestion to specimens from patients receiving ethylene diamine tetra-acetate (EDTA) therapy. The entire procedure is performed in a single tube and provides sufficient concentration of lead to yield adequate absorbance values without scale expansion. Completeness of extraction in the presence and absence of chelating agents has been established with the isotope Pb. 210 This procedure has been applied both to the diagnosis of lead poisoning and to the monitoring of lead excretion in patients receiving chelation therapy.

Determination of Lead Content of Foodstuffs

Determination of Lead Content of Foodstuffs