Cobre e seu uso na dieta de frangos de corte (Gallus gallus) Revisão de literatura / The use of copper on broiler (Gallus gallus) diets ­ A literature review / Cobre y su uso en la dieta de pollos de engorde (Gallus gallus) - Revisión de literatura

O cobre é um mineral essencial ao metabolismo e seu uso tem sido associado à melhora do desempenho zootécnico, aumento da resistência ao estresse e doença nas aves. A indústria avícola com o intuito de maximizar o desempenho produtivo formula normalmente as dietas com altas doses da fonte inorgânica de cobre, o que contribui para o desequilíbrio metabólico e como consequência aumenta a poluição ao meio ambiente. Dessa forma, o uso de fontes orgânicas de cobre tem sido estimulado. Sendo assim, o objetivo do presente trabalho foi revisar a utilização do cobre na dieta de frangos de corte com enfoque para os benefícios das fontes orgânicas. Conclui-se que fontes mais biodisponíveis de cobre são uma oportunidade para diminuir sua inclusão, mantendo o desempenho do animal, por meio da redução de agentes patogênicos, melhora na digestibilidade e redução ao impacto ambiental em dietas de frango de corte.(AU)

Copper is an essential mineral for the metabolism and its use has been associated with improved zootechnical performance and increased resistance to stress and diseases in broilers. In order to maximize the productive performance, poultry nutritionists usually formulate diets with high doses of copper inorganic sources, contributing thereby to favor metabolic imbalance and environmental pollution. The purpose of this study was to review the use of copper in broiler diets with a focus on the benefits of organic sources. It can be concluded that more bioavailable sources of copper represent an opportunity to reduce its inclusion without compromising animal performance. Moreover, proper management of copper in broiler diets can contribute to reduce pathogens, improve digestibility and reduce the environmental impact of the poultry industry.(AU)

El cobre es un mineral esencial al metabolismo y su uso se ha asociado a mejora del desempeño zootécnico, aumento de la resistencia al estrés y enfermedades en las aves. La industria avícola con el fin de maximizar el rendimiento productivo, formula normalmente las dietas con altas dosis de fuente inorgánica de cobre, lo que contribuye al desequilibrio metabólico y como consecuencia aumenta la contaminación para el medio ambiente. Por lo tanto, el uso de fuentes orgánicas de cobre ha sido estimulado. Así, el objetivo de este estudio fue revisar el uso de cobre en la dieta de pollos de engorde, con enfoque para los beneficios de las fuentes orgánicas. Se concluye que las fuentes más biodisponibles de cobre son una oportunidad para reducir su inclusión, manteniendo el rendimiento de los animales a través de la reducción de agentes patógenos, digestibilidad mejorada y reducción al impacto ambiental en dietas de pollo de engorde.(AU)

Prevalencia de deficiencia y consumo de hierro, zinc y cobre en mujeres chilenas en edad fértil / Prevalence of deficiency and dietary intake of iron, zinc and copper in Chilean childbearing age women

El objetivo del presente estudio es evaluar el estado nutricional e ingesta de hierro (Fe), zinc (Zn) y cobre (Cu) en mujeres chilenas en edad fértil. Se estudió una muestra de conveniencia de 86 mujeres entre 18 a 48 años de edad de la ciudad de Santiago, Chile. El estado nutricional de Fe se determinó a través de hemoglobina (Hb), volumen corpuscular medio, saturación de transferrina, zinc protoporfirina, ferritina sérica (FS), Zn y Cu séricos. La ingesta dietética fue evaluada con una encuesta de frecuencia de consumo. Un 4,7% de las mujeres presentó anemia por deficiencia de Fe, 21% deficiencia de Fe sin anemia, 26% depósitos depletados de Fe y un 48,3% estado nutricional normal de Fe. Las mujeres obesas presentaron mayores niveles de FS (p<0,01) al comparar con mujeres con peso normal. Además, presentaron niveles más altos de Hb (p<0,05) al comparar con mujeres con estado nutricional normal y sobrepeso. El 3,5% y 2,3% de las mujeres presentó deficiencia de Zn y Cu, respectivamente. El 95%, 94% y 99% cumplió el EAR para Fe, Zn y Cu, respectivamente. No se encontraron diferencias significativas en la ingesta de micronutrientes entre las mujeres al comparar por estado nutricional. En conclusión, un alto porcentaje de las mujeres presentó una ingesta adecuada de micronutrientes. Además existe una baja prevalencia de deficiencia de Zn, Cu y anemia. Sin embargo, un 47% presenta deficiencia de Fe en etapas anteriores a la de anemia.

The aim of the present study was to evaluate anemia, the biochemical status and dietary adequacy of iron (Fe), zinc (Zn) and copper (Cu), in Chilean childbearing age women. We studied a convenience sample of 86 women aged 18 to 48 years from Santiago, Chile. We determined anemia and the micronutrient status through hemoglobin (Hb) mean corpuscular volume, transferrin saturation, zinc protoporphyrin, serum ferritin (SF), serum Zn and Cu. Dietary adequacy was estimated using a food frequency questionnaire. Of all women, 4.7% had Fe deficiency (ID) anemia, 21 % ID without anemia, 26 % depleted Fe stores and 48.3% normal Fe status. Obese women had higher SF (p<0.01) compared with those classified as having normal BMI. Also, showed higher Hb (p<0.05) concentrations compared with overweight and normal weight women. Participants showed 3.5 % and 2.3 % of Zn and Cu deficiency, respectively. Also, 95 %, 94 % and 99 % had adequate intake of Fe, Zn and Cu respectively, according to EAR cut points. There were no significant differences in micronutrients intake across different nutritional status. There was a low prevalence of anemia, Fe, Zn and Cu deficiency. A high percentage of women reached micronutrient adequacy. However, 47% of women had ID without anemia and Fe depleted stores.

Valores de referencia de hierro, yodo, zinc, selenio, cobre, molibdeno, vitamina C, vitamina E, vitamina K, carotenoides y polifenoles para la población venezolana / Reference values of iron, iodine, zinc, selenium, copper, molybdenum, vitamin C, vitamin E, vitamin K, carotenoids and polyphenols for the Venezuelan population

Esta revisión de las recomendaciones de energía y nutrientes para la población Venezolana presenta los valores de hierro, yodo, zinc, selenio, cobre, molibdeno, vitamina C, vitamina E, vitamina K, carotenoides y polifenoles. Se adoptan definiciones internacionales de Ingestas Dietéticas de Referencia (DRIs por Dietary Reference Intakes) que incluyen: Ingesta Dietética Recomendada (RDA), Requerimiento Promedio Estimado (EAR), Ingesta Adecuada (AI) y Niveles de Ingesta Máximos Tolerables (UL). Las RDA para hierro: 11 mg/día para < 1 año, 7-10 mg/día niños, 8-11 mg/día para hombres, 8-18 mg/día para mujeres y 27 mg/día para embarazadas. RDA Yodo: 110-130 mg/ día recién nacidos, 90-120 mg/día niños y adolescentes y 150 mg/ día adultos, 220 mg/día embarazo y 290 mg/día lactancia. RDA Zinc: 2-3 mg/día < 1 año, 3-5 mg/día niños, 8-11 mg/día adolescentes y hombres, 8-9 mg/día adolescentes y mujeres, 12 mg/ día para embarazadas y 13 mg/día durante la lactancia. RDA Vitamina C: 40-50 mg/día recién nacidos, 15-45 mg/día niños, 75 mg/día adolescentes masculinos, 65 mg/día adolescentes femeninas, 90 mg/día hombres y 75 mg/día mujeres, 80-85 mg/día embarazadas y lactancia 115-120 mg/día. También se presentan valores de cobre, selenio, molibdeno, vitaminas E, K, carotenoides y polifenoles. Estas recomendaciones contribuirán al diseño de políticas adecuadas y eficientes que puedan ayudar a evitar o a tratar las consecuencias derivadas de la deficiencia o el exceso de estos nutrientes.

The review on iron, iodine, zinc, selenium, copper, molybdenum, vitamin C, vitamin E, vitamin K, carotenoids and polyphenols recommendations for Venezuela comprise the definitions adopted worldwide known as Dietary Reference Intakes (DRIs) that include Recommended Dietary Allowance (RDA), Estimated Average Requirement (EAR), Adequate Intake (AI) and Tolerable Upper Intake Levels (UL). The RDA for iron: 11 mg/day for infants < 1 year of age, 7 - 10 mg/day for children, 8-11 mg/day for males, 8-18 mg/day for females and 27 mg/day during pregnancy. RDA for iodine: 110-130 mg/day for infants, 90-120 mg/ day for children and adolescents, 150 mg/day for adults, 220 mg/ day for pregnancy and 290 mg/day during lactation. RDA Zinc: 2-3 mg/day for infants, 3-5 mg/day for children, 8-11 mg/day for male adolescents and adults, 8-9 mg/day for female adolescents and adults, 12 mg/day during pregnancy and 13 mg/day for lactation. RDA Vitamin C: 40-50 mg/day for infants, 15-45 mg/ day for children, 75 mg/day for male adolescents, 65 mg/day for female adolescents, 90 mg/day for adult males, 75 mg/day for adult females, 80-85 mg/day during pregnancy and 115-120 mg/ day during lactation. Recommendations for copper, selenium, molybdenum, vitamins E, K, carotenoids and polyphenols are also presented. These recommendations will help to design adequate and efficient policies that could help to avoid or to treat the consequences derived from the deficiency or the excess of these nutrients.

A importância do cobre na dieta alimentar. Revisão / The importance of copper in the diet. Review

Os íons metálicos são necessários para muitas das funções vitais do organismo humano. A ausência de alguns deles pode ocasionar sérias doenças, tais como: anemia, por deficiência de ferro; retardamento do crescimento de crianças, por falta de zinco; e má formação óssea em crianças, por falta de cálcio. Alguns metais e semi-metais, por sua vez, quando presentes no organismo humano, podem causar intoxicações. São exemplos clássicos: o arsênio, o chumbo, o cádmio e o mercúrio. Neste artigo, são apresentadas algumas das funções desempenhadas pelo metal cobre, assim como os principais alimentos necessários em nossa dieta alimentar, que contém este metal. O cobre é um dos principais metais presentes no corpo humano. Encontra-se distribuído praticamente em todo o organismo, mas em diferentes concentrações, o que indica seu papel funcional. As atividades protéicas como; a tirosinase, a citocromo oxidase e a ceruloplasmina, são basicamente regidas pelo cobre. Apesar da grande importância no corpo humano, seu excesso no organismo é nocivo, pela interferência nas atividades catalíticas normais de algumas enzimas. A presente revisão teve como principal objetivo levantar as questões de responsabilidade social de quanto são necessárias pesquisas periódicas para re-avaliar a composição dos alimentos e o controle da sua qualidade; estudos, não só no que diz respeito ao cobre, mas, no âmbito metais, pois sua essencialidade faz parte da nossa realidade e sua importância é vital para a humanidade.

Suplementación con cobre entre comidas no tiene efecto sobre la nutrición de hierro en hombres / Copper supplementation between meals has no effect on iron status of men

Iron deficiency is prevalent in most of the developing world where it coexists with other micronutrient deficiencies such as copper. Combined supplementation with iron and copper is one of the strategies that can be used to improve the iron and copper status of a population. However, there is concern about potential negative interactions between these two micronutrients due to a competitive binding to the divalent metal transporter 1 (DMTl), a proton-coupled transporter of a variety of divalent metals including copper. The aim of this study was to measure the effect of daily supplementation with 8 mg of copper, as copper sulfate during 6 months on the iron status. Sixty healthy male adults were randomized to receive a copper supplement or a placebo. Fasting blood samples were obtained before and after copper supplementation to evaluate the iron and copper nutritional status. Copper supplementation did not change significantly iron and copper status parameters. In conclusion, daily supplementation with 8 mg of copper during 6 months does not deteriorate iron nutrition in adult men.

La deficiencia de hierro coexiste con otras carencias, entre ellas de cobre. La suplementación combinada con estos nutrientes es una de las estrategias utilizadas en su prevención. Sin embargo, existe la posibilidad de interacciones negativas, ya que el DMT1, principal transportador de hierro no hem a nivel intestinal, también transporta cobre. El propósito del estudio fue medir el efecto de la suplementación con 8 mg diarios de cobre, como sulfato de cobre, durante 6 meses, sobre la nutrición de hierro. Sesenta hombres adultos, aparentemente sanos, fueron seleccionados al azar para recibir el suplemento de cobre o un placebo. Se tomaron muestras de sangre en ayunas antes y después de finalizada la suplementacion para evaluar la nutrición de hierro y de cobre. La suplementacion con cobre no determinó cambios significativos en los indicadores de nutrición de cobre y de hierro. En conclusión, la suplementacion con 8 mg diarios de Cu administrado entre comidas durante 6 meses no deterioró la nutrición de hierro en hombres adultos.

Determinação dos elementos-traço ferro, zinco e cobre em fórmulas infantis para lactentes, leites em pó e alimentos infantis: análise comparativa com a rotulagem / Determination of elements iron, zinc and copper in infant formula for infants, milk powder and infant foods: comparative analysis with the labeling

Os elementos-traço Cu, Fé e Zn têm importante papel no crescimento e desenvolvimento na infância. Atualmente a inserção de alimentos complementares é realizada muito cedo na alimentação das crianças. Este trabalho avaliou a rotulagem nutricional de fórmulas infantis para lactentes, alimentos infantis e leites em pó disponíveis no mercado, determinando os elementos traço Cu, Fé e Zn por espectrofotometria de absorção atômica. Foram observadas diferenças entre os teores informados nos rótulos e os encontrados na análise, além de ampla falta de informação de elementos traço nas rotulagens.

Avaliação dos teores totais de cobre, ferro e zinco em chás de erva medicinais / Evaluation of total contents of copper, iron and zinc in teas of medicinal grass

As ervas medicinais vêm sendo amplamente estudadas e comercializadas em nosso país. A maioria destes estudos versa sobre seus ativos, normalmente compostos orgânicos de funções diversas no organismo. Cada vez mais as aplicações das diversas ervas medicinais de nossa flora vêm se ampliando e grupos de interesse nesta área vêm aumentando. Antes, o uso de chás era através de indicações caseiras; atualmente, além dos conhecimentos de uso popular destas ervas, várias pesquisas são feitas na área farmacológica, visando conhecer e aumentar o campo de atuação destas plantas. No que diz respeito à composição dos elementos traços nessas plantas, existem estudos, mas ainda precários. O cobre, ferro e zinco são elementos essenciais a diversas funções do organismo. Sabendo da importância destes, o presente trabalho tem como objetivo avaliar o teor de cobre, ferro e zinco em chás de ervas medicinais.(...).

Concentracion sérica de cobre ®libre¼ y ceruloplasmina en niños con desnutricion aguda grave antes de iniciar la terapia nutricional y al momento de recuperar el apetito en turbo, antioquia, colombia / Serum concentrations of free copper and ceruloplasmin in children with severe acute malnutrition before nutritional therapy and after children have recovered the apetite in turbo, antioquia, colombia

Introduction: copper supplementation therapy has been used in children with acute and severe malnutrition. Scientific evidence has shown that malnourished children with edema have free copper in plasma which could produce oxidative stress. Objective: To compared plasma concentrations of free copper between children with acute and severe malnutrition and a control group. Methodology: Cross sectional study where 66 normal and malnourished children were studied. A longitudinal study (before and after type) design was used including 40 children with severe and acute malnutrition; free copper was merasured by high-resolution capillary electrophoresis; ceruloplasmin and PCR by nephelometry. Results: In the cross sectional study children with marasmus had higher free copper serum concentrations than children with oedematous malnutrition, but the difference was not significant. In the control group this metal was not found. Children with oedema showed significant lower ceruloplasmin concentrations than children with marasmus (p=0.00) while the difference in PCR was also no significant for both groups. When the relationship between free copper serum concentrations and the presence of infection was analyzed no significant differences were obtained. However, serum albumin concentration was significantly lower for children with oedematous malnutrition than the marasmic group (p=0.016). After children recovered the appetite in the longitudinal study, serum free copper concentration decreased for both groups and ceruloplasmin concentration increased but no significant differences were observed. Conclusion: Copper supplementation could be considered as nutritional therapy for undernourished children since the beginning of the nutritional treatment, as it is recommended by WHO.

Introducción: La recuperación de los niños con desnutrición aguda grave incluye suplementación con cobre desde el inicio de la terapia; existen evidencias que niños edematosos pueden tener cobre libre en plasma el cual podría generar estrés oxidativo. Objetivo: Comparar concentraciones séricas de cobre libre y ceruloplasmina en un grupo de desnutridos agudos graves y un grupo control Metodología: estudio transversal al ingreso entre niños con y sin desnutrición en una muestra de 66 sujetos y longitudinal de tipo antes y después en 40 niños desnutridos. Se determinó cobre libre por electroforesis capilar de alta resolución; ceruloplasmina y PCR por nefelometría, además de variables clínicas Resultados: En el transversal, los marasmáticos presentaron niveles de cobre libre mayores que los edematosos sin diferencia significativa; en el grupo control este metal no se detectó. En los edematosos la concentración de ceruloplasmina fue significativamente menor con relación a los marasmáticos (p=0.00) y la PCR no presentó diferencia significativa entre ellos. No se encontraron diferencias significativas entre los niveles de cobre libre y presencia o no de infección. La albúmina se encontró más baja en los edematosos con diferencia significativa respecto a los marasmáticos (p=0.016). En el longitudinal, al recuperar el apetito el cobre libre disminuyó y la ceruloplasmina aumentó en los dos grupos sin diferencia significativa Conclusión: el suplemento de cobre como componente de la terapia nutricional puede ser suministrado a los desnutridos desde el inicio como lo propone el protocolo de la OMS.

Efecto de la suplementación con cobre sobre los valores de presión arterial en pacientes con hipertensión moderada estable / Effect of cooper supplementation on blood pressure values in patients with stable moderate hypertension

Copper (Cu) deficiency is associated with changes in arterial pressure. The effect depends of the age of initiation of the copper-deficient diet. Copper deficiency started at a young age causes hypotension. When initiated in older or adult animals, copper deficiency can cause hypertension. A case-control study was carried out to investigate the effect of administrating 5 mg Cu/d in 60 subjects, both genders, with mild stable hypertension, pharmacologically untreated (treated group) and compared with 60 hypertensives (control group) who were matched by gender, age, body weight, smoking habits, calories, fat and salt intake (NaCl), and physical activity. Hypertension was diagnosed when the blood pressure was > 150/95 mm Hg. Mean age, mean corporal weight and risk factors were similar in both groups. The results suggested the existence of a marginal deficiency of the trace element in 62 per cent of subjects and demonstrated that Cu decreases systolic (r = -0.963) and diastolic (r = -0.981) blood pressures in treated group (p < 0.05). Control patients did not show significant changes in their arterial pressures. These findings indicate a functional alteration in human blood pressure regulation during mild copper depletion and suggest that Cu could be used in the treatment of stable moderate arterial hypertension. Further investigation is needed to determine the extent of this influence.

Clinical studies of [procopper iud] and in-vivo evaluation of levonorgestrel and copper levels in different biological fluids

The clinical studies of procopper IUDs revealed that they decreased the menstrual flow, but not to the extent of amenorrhea, no pregnancy was reported and they diminished pelvic inflammatory disease [PID]. The in vivo release study of both levonorgestrel as well as copper released from procopper IUDs in biological fluids indicated that neither levonorgestrel nor copper interfered with the release of each other, indicating that there is no interaction between them

Estudo morfométrico de fetos de ratos após administração prenatal de cobre / Morphometric study of fetuses after prenatal administration of cooper in rats

A administração endovenosa de sulfato de cobre (4mg/kg de peso) a ratas grávidas, provocou diminuição significativa dos pesos do feto e da placenta e do comprimento do cordão umbilical

Classificaçäo das ligas para fundiçäo com alto conteúdo de cobre de uso odontológico, em conseqüência da capacidade de sofrerem branidura / Classification of high copper casting alloys in function of their ability to be burnished

Estabeleceu-se uma escala numérica para a classificaçäo de cinco ligas com alto conteúdo de cobre e uma experimental, contendo berílio, usadas em fundiçäo, em conseqüência da capacidade de sofrerem branidura. Para tanto, obteve-se o número de branidura de cada uma das ligas por meio da divisäo da dureza Brinell pela porcentagem de alongamento. Segundo este método, quanto maior o número, maior a dificuldade de se brunir a liga. Os valores foram obtidos sob duas condiçöes de tratamento durante o resfriamento, um rápido, em que, após a solidificaçäo, a liga era resfriada bruscamente em água, e um lento, em que se deixava a liga esfriar lentamente até a temperatura ambiente. Verificou-se que as ligas apresentaram números de brunidura diferentes, e que os tratamentos durante o resfriamento näo os influenciavam, com exceçäo da liga Idealloy, cujos valores säo diferentes

Zinc, copper & iron contents in cooked foods & estimates of their daily intakes in young hostel residents.

Dietary zinc, copper and iron intakes of 19 men and 11 women (aged 18-25 yr) were determined during three periods of five consecutive days each, using, weighment method and atomic absorption analysis of food samples. Daily zinc, copper and iron intakes of men ranged from 13.1 +/- 1.2 to 15.3 +/- 1.4 mg/d, 1.62 +/- 0.15 to 1.84 +/- 0.17 mg/d and 20.5 +/- 2.8 to 29.1 +/- 4.5 mg/d and of women 8.8 +/- 2.0 to 9.0 +/- 1.6, 1.42 +/- 0.23 to 1.69 +/- 0.62, and 10.0 +/- 2.4 to 14.7 +/- 2.6 mg/d respectively. Cereals provided 67.7 per cent of dietary zinc, 47.7 per cent copper and 62 per cent iron in men and 60 per cent of Zn, 44 per cent of Cu and 59 per cent of Fe in women, suggesting lower contribution of cereals to Cu intakes than Zn and Fe. Men had mineral intakes close to the recommended allowances for Indians, whereas the intakes of women were 30 to 60 per cent lower. When expressed as mg/1000 kcal, lower calorie intakes of women were responsible for their low mineral intakes. Intra-individual variation in mineral intakes was higher (18.39%) than that of energy intakes (14-17%) in both men and women. Phytate: Zn molar ratios were > 15 indicating risk of zinc deficiency in these students.

Deficiencia de cobre en bovinos: su tratamiento comparativo con cuprum y cobre alopático / Deficit of copper in bovine: comparative treatment with cuprum and allopathic copper

En un establecimiento con deficiencias primarias y secundarias de cobre se compararon dos tratamientos, uno homeopático y el otro alopático, frente a testigos no tratados. De los resultados se desprende: 1.- En el tratamiento alopático la ganancia diaria de peso (G.D.P.) es mayor que en el tratamiento homeopático al comenzar el ensayo. 2.-Hacia el final del mismo, las G.D.P., es mayor en el tratamiento homeopático que en el alopático. 3.- Ambas G.D.P. son mayores que la de los testigos

Effects of nutritional copper deficiency on adult non-pregnant and pregnant rats and their newborns

Se estudiaron los efectos de la deficiencia nutricional de cobre sobre la ganancia de peso, ingesta de alimento y fertilidad de ratas Wistar adultas, preñadas y sin preñar, y peso de sus recién nascidos. Los animales adultos fueron sumetidos a dietas con diferentes contenidos de cobre (control - 5 ppm; deficiencia moderada - 1.2 ppm; deficiencia severa - 0.3 ppm) durante seis semanas (no preñadas) y nueve semanas (preñadas). No se observó ningún efecto sobre la ganancia ponderal ni sobre el apetito del grupo de animales sujetos a deficiencia de cobre. Ni la fertilidad, evaluada por el número de conceptus y nascidos vivos de las ratas preñadas, ni el peso de sus recién nascidos, sufrieron ningún trastorno. Estos datos revelan que no sólo es el grado de deficiencia, sino también el período durante el cual es impuesto, al igual que su duración, los factores que condicionan la aparición de alteraciones propias de esta deficiencia

Effect of dietary zinc and copper on peripheral blood plasma cholesterol, testosterone and histomorphology of testes in rats.

Total plasma cholesterol (mg/dl) significantly (P less than 0.01) decreased from 70.8 to 54.01 as the dietary Cu levels increased from 2.5 to 5 ppm at 12 pm Zn concentrations in male weanling rats. A similar trend was observed in the blood peripheral testosterone concentration at 12 ppm Zn and 2.5 ppm Cu. Histological examination of testes revealed smaller seminiferous tubules with atrophy of germinal epithelium. Also a marked loss of spermatogenic cells was observed in Zn and Cu deficient rats.

Determination of iron, copper and zinc in human whole vitreous humor by flow injection atomic absorption spectrometry

Vitreous humor is analized for iron, copper and zinc by flow injection atomic absorption spectrometry. Optimal conditions for the determination of these elements were established. The sample is injected as a discrete slug into a carrier stream of water. Standards and samples are matched in physiological concentrations of some chemical species. The effect of viscosity was studied by preparing standards in glycerol, hyaluronic acid and chondroitin sulfate at different concentration. Glycerol was found to be more convenient for preparation of viscosity-controlled standards. Recorveries are 95 to 105 per cent. The flow injection determination of iron, copper and zinc in vitreous body is reproductible, simple and quick, can be performed using microsamples and give more precise results than conventional colorimetric methods