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Se evaluó el desempeño de floculantes aniónicos y catiónicos; en presencia de coagulantes, con el fin de utilizarlos en el tratamiento de agua residual. Se utilizó el floculante aniónico AN934 y a la par se deja fija la concentración de FeCl3 el cual actúa como coagulante, asimismo se estudió el uso de floculante catiónico con nombre comercial Fluxol C650 que pertenece a la familia de las poliacrialmidas, dichos tratamientos se aplicaron a muestras de agua residual domestica de la ciudad de Tijuana provenientes de la alcantarilla municipal, se midieron los parámetros como son: turbiedad, pH, color y sólidos suspendidos, con la finalidad de reducirlos mediante la metodología de la prueba de jarras. Ambos floculantes funcionan en un amplio intervalo de pH, reduce el uso de sales inorgánicas, presentan alta solubilidad en agua y muy buena velocidad de sedimentación. Los flóculos formados con el AN934 son gruesos a diferencia de los flóculos formados utilizando Fluxol C650.

En el análisis cuantitativo de una mezcla binaria de metformina (Met) y sitagliptina (Sgt) mediante la técnica de espectrometría derivada, se utiliza el método de punto de anulación de la primera o segunda derivada. Una de las ventajas de esta técnica es que la derivada mide la pendiente espectral y por ello la meseta de un espectro de absorción; el máximo y mínimo de la primera derivada corresponde a los puntos de inflexión del espectro y para el caso de la segunda derivada corresponde a la curvatura del espectro original. En este trabajo se estudió primeramente los métodos de extracción de principios activos en tabletas combinadas utilizadas para controlar la diabetes Mellitus tipo 2 con su posterior aplicación del método modificado de espectrofotometría de relación derivada con adición de estándar para la sitagliptina; esto se hace por la composición de la tableta (Sgt - Met 50 mg - 850 mg).

Estimadas lectoras y estimados lectores. Para nosotros es un gran gusto escribir estas líneas que presentan este número especial, resultado de la colaboración de la Asociación Mexicana de Química Analítica con la revista Pädi, de la Universidad Autónoma del Estado de Hidalgo. Esperamos que sea de su interés. ¿Qué es la Química Analítica, en la actualidad? La Química Analítica es una disciplina que muchos confunden con el campo del conocimiento que se conoce como Análisis Químico. Sin embargo, durante el siglo XX el enfoque y concepción de lo que hoy llamamos Química Analítica evolucionó desde el Análisis Químico (concebido como una subdisciplina de la Química) hasta una interdisciplina que se relaciona con disciplinas tales como la Biología, las Ciencias de la Salud, diversas Ingenierías, las Ciencias Ambientales, las Ciencias Forenses y las Ciencias Aduanales, entre muchas otras. Fue así como la revista Pädi, así como el Comité Directivo y la Junta de Representantes de la AMQA convocaron a los socios de esta última para que sometieran sus trabajos como artículos que pasarían por un arbitraje doble ciego, para su posible publicación en un número especial de la revista. Además, la Junta de Representantes de la AMQA escogió trabajos de alumnos de licenciatura que, a su juicio, tuvieran la calidad suficiente para ser sometidos a este tipo de evaluación por pares. La convocatoria consideraba las siguientes áreas, entre otras: Alimentos Medicina, farmacia y salud Educación Estudios fundamentales Aplicaciones diversas Ambiental

The research and design of new combined products are of high interest and importance for public health. That is why the design of new technologies in medical devices requires the use of robust procedures, such as the use of ionizing radiation. These methodologies favor the modification of the surface of the medical device for the incorporation of analgesic, anti-inflammatory, and antimicrobial drugs. These medical devices will have the ability to generate prophylactic effects against inflammatory and infectious processes when patients undergo a surgical medical procedure. That is why the FDA describes a combination product as “therapeutic and diagnostic products that combine drugs, devices, and biological products.” In this chapter, the characteristics and advantages of using the different ionizing radiation methodologies mentioned previously for designing these new drug-medical device combination products are explored. In the same way, quality control tests are described for these products at the research or industrial level.

On the basis of the absorbance activity law, it is possible to carry out the spectrophotometric determination of two individual components (having totally or partially overlapping spectra) in a binary mixture. This determination can be carried out in a very precise and simple way by introducing ourselves in the multicomponent analysis by means of the so-called multi-wavelength linear regression analysis (MLRA) method that allows easy handling of data obtained at different wavelengths and whose results are comparable in accuracy and precision with other mathematical procedures. Another way of being able to calculate the individual concentration of two components is a mixture when their spectra are totally or partially overlapping; it is the derived spectrophotometry. The objective of this work is to apply the MLRA method for the individual determination of a binary mixture of metformin and sitagliptin as well as to apply derived spectrophotometry.

Herein, a new method for the determination of formaldehyde in drinking water was proposed by sequential injection analysis using a fluorescent filter detector. The method allowed the determination of formaldehyde at 0.05 mg L−1, which is below the permissible limit of formaldehyde in drinking water (0.9 mg L−1), without a preconcentration step. The method was optimized using factorial designs evaluating the principal factors: 2,4-pentanedione concentration, volume of the reagent and buffer, reaction pH, temperature and aspiration sequence. A twice injection of the sample at the beginning and end of the sequence allowed the quantification of formaldehyde at 0.05 mg L−1. Once the method was optimized, it was validated using the principal parameters such as linear range (from 0.05 mg L−1 to 1.0 mg L−1); detection limit (0.01 mg L−1); intra-laboratory reproducibility of 6.73% and recoveries between 86% and 124% for different samples of drinking water. The method is simple and it can be easily implemented in routine laboratories, and it could be easily automated.

Nanoparticles formed from lipids are currently applied successfully to deliver drugs. The particle size of the nanoparticle system is an essential characteristic to enhance the entrance of the drugs inside tissues and cells. Using design of experiment is appealing to find the specific conditions to optimize particle size of drug-loaded nanoparticles. Authors of this chapter applied a fractional factorial design of half fraction 24-1 with levels between continue factors, finding statistically significant differences for two factors such as concentrations of drugs and type of solvent where the organic phase is dissolved. This design shows the optimization of a formulation of capsaicin in solid lipid nanoparticles. The chapter also includes information on methods to prepare solid lipid nanoparticles (SLN), the variables involved, and a selection of studies about optimization of SLN formulations.

This chapter presents the optimization of the hydrodynamic and chemical parameters of the FIA system in the determination of copper and manganese in wine samples by VIS spectrophotometry. This technique has been based on the injection of liquid samples in the non-segmented movement, within a continuous carrier current of a suitable liquid. The injected sample forms a zone that disperses on its way to a detector. The later continuously records the absorbance or other physical parameters, since it continuously passes the sample material through the flow cell, using the factorial designs Plackett-Burman, Box-Behnken, and the factorial design 2^4. The methods have the advantages of low-cost, easy availability of chemicals, and instrumentation and straightforward application to real samples.

Poly(methacryloiloxy-o-benzoic acid), an amphiphilic weak polyelectrolyte was bound by secondary forces to cationic drugs (propranolol. HCl and labetalol.HCl) to form water-insoluble complexes that release the bound drug only in ionic media. Compressed tablets were prepared from the polymer-drug complexes formed. The complex with propranolol suffers a fast release in simulated gastric fluid (pH 1.2), but presents a diffusion controlled release at pH 6.8 and 7.4. Moreover, the complex with labetalol (a less water soluble drug) presents controlled release at the three pH values studied. In this case, release is controlled by the erosion of the tablets. The results indicate that PMAOB is a good carrier for oral release of poorly soluble cationic drugs.

Plackett-Burman and Quarter fraction 2 5−2 factorial designs were applied to evaluate a spectrophotometric flow injection method in order to determine phenol in water by using 4-aminoantipyrine (4-aap) as derivatizing reagent. With a minimum number of experi- ments, the designs enabled the best conditions for phenol analysis: 80 cm and 180 cm reactors; flow-rates being: NH3 1.0 mL min −1 ; 4-aap 0.35 mL min −1 and K3(Fe(CN)6) 0.35 mL min −1 , (NH3) 0.064 mol L −1 , (4-aap) 9.84 × 10 −3 mol L −1 , (K3(Fe(CN)6)) 0.02 mol L −1 , and an injection volume of 200 µL. With the optimized method it was possible to increase the lineal range from 0.3 µg mL −1 to 30 µg mL −1 and also to quantify the maximum allowable phenol concentration in water in comparison with other standard and flow injection methods whose lineal range are from 0.5 µg mL −1 to 20 µg mL −1 and from 0.5 µg mL −1 to 16 µg mL −1 , respectively. The detection limit was of 0.13 µg mL −1 and the regression coefficient was of 0.9999, making possible a throughput of 36 determinations an hour with a minimum consume of reagent. With the proposed method, a distillation step was not necessary to remove sulfates but, when the sulfate:phenol ratio was higher than 83, the analytical signal for phenol increased 8%, but hypochlorite interfered with the signal when the hypochlorite:phenol ratio was higher than 1. Resumen. Se utilizaron disenos factoriales Plackett-Burman y frac- cionado 2 5−2 para evaluar un metodo espectrofotometrico de inyec- cion en flujo con el objetivo de determinar fenol en agua utilizando 4-aminoantipirina (4-aap) como reactivo derivatizante. Los disenos establecieron, con la menor cantidad de experimentos, las mejores condiciones para el analisis de fenol fueron: reactores de 80 cm y 180 cm; caudales para NH3 de 1.0 mL min −1 ; para 4-aap de 0.35 mL min −1 y para K3(Fe(CN)6) de 0.35 mL min −1 ; las concentraciones optimas fueron NH3 0.064 mol L −1 , 4-aap 9.84 × 10 −3 mol L −1 y K3(Fe(CN)6) 0.02 mol L −1 con un volumen de inyeccion de 200 µL. El metodo una vez optimizado permitio incrementar el intervalo lineal de 0.3 µg mL −1 a 30 µg mL −1 en comparacion con otros metodos estandar y de flujo continuo cuyos intervalos lineales son de 0.5 µg mL −1 a 20 µg mL −1 y de 0.5 µg mL −1 a 16 µg mL −1 , respectivamente. El limite de detec- cion fue 0.13 µg mL −1 y el coeficiente de regresion 0.9999, con una frecuencia de muestreo de 36 determinaciones por hora y un minimo consumo de reactivos. Con el metodo propuesto no fue necesario un paso de destilacion para remover sulfatos pero cuando la proporcion de sulfato:fenol fue mayor a 83 la senal analitica para fenol incremento 8%. El hipoclorito interfirio en la cuantificacion de fenoles cuando la proporcion hipoclorito:fenol fue mayor a 1. Palabras clave: Diseno factorial Plackett-Burman, fenol, 4-aminoan- tipirina, agua, inyeccion en flujo,espectrofotometria.

The high sensitivity C-reactive protein (hs-CRP) is an important biomarker in inflammatory processes. The objective was to analyze the relationship between the concentrations of hs-CRP in adults from a northern Mexico region with their typical food intake patterns. A sample of 72 university professors underwent clinical and anthropometric assessments and their hs-CRP levels were quantified with an immunoenzymometric assay. Additionally, they filled out a food intake frequency questionnaire, from which the servings of different food groups were obtained with the ESHA software. The average age of participants was 49.75 +/- 10.05 years and the average hs-CRP concentration was 1.66 (0.97, 3.52) mg/L. The value of the association between fruit consumption and hs-CRP level was protective, according to the logistic regression analysis, being the Odds Ratio (OR) 0.23 (95% CI: 0.05, 1.03); while for vegetables the OR was 0.66 (95% CI: 0.12, 3.68). Furthermore, high protein content foods, dairy products, oils and fats were associated with elevated levels of hs-CRP. In conclusion, in our study, the intake of some food groups like fruits and vegetables, and to a lesser extent cereals, were associated with low values of hs-PCR.