A daily product that we consume in our body such as honey may contain heavy metals. Release of heavy metals caused by pollution into the foods we ingest can cause serious risks at high concentrations. Some of these risks include damage to the organs, development or enhancement of illnesses. The purpose of this study is to analyze how different regions with different levels of pollution affect levels of copper in raw honeys. The honeys we tested are divided into three different categories according to the areas that they were collected from: rural, suburban, urban. The samples were digested using reflux with and HNO₃ and H₂O₂. Then they were diluted and filtered if necessary, making them ready for analysis by Atomic Absorption Spectroscopy for copper. The results suggested that the honey with the highest concentration of Cu was from an urban area, the honey from a rural setting had the least amount of Cu and the honey from the suburb was in the middle of the two. The concentration of Cu in the 3 grams of honey we analyzed ranged from 0.2-0.4 ug/g which is in the safe amount of Cu to intake in your body because the upper limit of safe amount of Cu in 3 grams is 300 ug/g. It’s important to be aware of the environment that your food comes from because the toxins in it can lead to serious risks.

Honey is naturally a sweet substance that is primarily produced by bees which they gather and refine using flower nectar. However, if bees collect nectar from plants grown in

contaminated soil or if the honey comes into contact with contaminated equipment during processing or packaging, it can contain heavy metals. This study’s purpose was to analyze metal contents in honey samples (local non-organic (LNO), international non-organic (INO), and international organic (IO) that are sold in local grocery stores. Two grams of each sample was prepared for analysis by AAS with use of a reflux digestion process that involved using an acid mixture of HNO3 and H2O2. Results for concentration of Pb in honey samples are INO (1.096 ppm), LNO (1.623 ppm), and IO (1.745 ppm). For concentration of Cu, LNO (0.992 ppm), IO (0.949 ppm), and INO (0.987 ppm). By looking at our results, it can be concluded that store bought honey is not safe for human consumption since it exceeds the limits of 0.1 ppm Pb content by FDA (Food and Drug Administration) guidelines.

Bees collect a variety of pollen to use as a protein source to feed broods; broods are young bees in development stages. The concentration of protein in pollen determines the health and strength of the broods. A slow or sharp decline in the concentration of protein in pollen can be detrimental to the younger bees’ survival due to a less fulfilling meal. An efficient and straightforward procedure that can be used to analyze the concentration of protein in pollen is the Bradford Assay. The Bradford Assay was used to find if there is a difference between the protein concentration in 2022 and 2023 pollen. Samples of pollen were treated with sodium hydroxide and centrifuged, this solution was then mixed with Bradford reagent. The Bradford reagent is a colored solution that changes color depending on the concentration of protein in the added solution. The concentration of protein in a pollen sample was determined by using visible spectroscopy. The pollen samples from 2023 were found to have a lower concentration of protein, on average, in their sample trial than pollen samples from 2022. Bee’s survival depends on the concentration of protein in pollen, the lowering of this concentration can lead to higher mortality rates in bee hives and can greatly affect the environment.

Honeybees are known to utilize pollen from flowers of varying protein concentrations to serve their colony and keep it thriving. While flower color preference has been observed for honeybees, less is known about how pollen color affects nutritional value – namely protein concentration; our research focuses on examining a link, if any, between pollen color and protein concentration. A Bradford Assay was used to analyze three different pollen samples: light yellow, dark yellow, and brown. Absorbance values were gathered at 590nm for BSA standards and pollen samples, and protein concentration was calculated. From our data, it is concluded that the light and dark yellow pollen samples had identical protein concentrations, and that the brown pollen, which was the darkest sample tested, reported the lowest protein concentration by a difference of 1.5% by mass. It is important to note that the absence of replicates in this experiment makes this conclusion tentative.

Dissolved oxygen (DO) levels play an important role in the well-being of rivers, lakes, oceans, and the marine life and vegetation that reside there. However, DO levels can be affected by many factors, such as pollution from industrial and agricultural sites close to water sources. Runoff of nutrients and other organic materials from agricultural sites, such as farms, can ultimately lower DO levels of nearby river water. Industrial pollution can release toxic chemicals such as lead that harm the ecosystem but have less effects on DO levels. The dissolved oxygen levels in different locations along the Snohomish River were analyzed to compare the DO levels in sites exposed to agricultural pollution versus industrialized pollution. Samples from 6 different sites were gathered from areas of the Snohomish River. Using a Winkler titration, the DO levels were found and compared between the different sites. Some industrial sites, notably Lowell Park, were found to have higher DO levels than the agricultural sites but overall no significant differences in the DO levels of agricultural and industrial sites in the Snohomish River were found. Although no significant differences were found in the DO levels of agricultural versus industrial sites in the Snohomish River, the DO levels of samples collected at a site located near a sewage plant appeared to have lower levels of DO than both the other industrial sites and the agricultural sites, implying that sewage plants could possibly release pollutants that lower the oxygen levels in river sites located nearby.

This project focused on testing the surface waters (about 0.5 m deep) along a waterway in the Lake Washington Watershed where there had not been any known BOD testing, for their Dissolved Oxygen (DO) and Biological Oxygen Demand (BOD). We included collection sites that were near areas sited for future restoration, as well as locations that have received recent restoration work. All the sites had varying degrees of wildlife–both plant and animal–living in the water, and so they were expected to be somewhat healthy locations. This was confirmed by our work, as all DO and BOD readings were within healthy limits. A closer look at our data can show how much BOD can fluctuate within a waterway depending on available nutrients, or if samples are taken from a lake or an estuary as opposed to a creek. Our data is only a small part of what can be learned by studying and monitoring these waterways, particularly as further restoration work continues.

Nucleophilic reactions with acid chlorides can react with a variety of weak/ strong nucleophile compounds while maintaining the high selectivity towards specific sites allowing for precise control over synthesized products. This research explores the selectivity of ester formation allowing for optimized reaction conditions using purification techniques and reactant concentrations in esterification processes, leading to improved yields and reduced unwanted product. The high reactivity of this reaction consequently may result in the formation of undesired byproducts if the reaction conditions aren't anhydrous and thermodynamically favored. The chlorine atom is electronegative which withdraws electrons from the carbonyl carbon and generates a partial positive charge. The alcohol acts as a nucleophile and attacks the electrophilic carbon atom of the acyl chloride forming a tetrahedral intermediate. The tetrahedral intermediate collapses and produces a good leaving group of a chloride ion. The present base triethylamine deprotonates the positively charged oxygen forming the product.

Esters, an important class of compounds widely used in various industries, can be synthesized through different methods using diverse carboxylic acid derivatives, such as using an amide or carboxylic acid.

This reaction is an example of a Nucleophilic addition reaction. This means that the driving force of this reaction is the exchange of elections for the sake of forming a more stable product. In a Nucleophilic addition reaction, a nucleophile (electron donor), an electrophile (acceptor of electrons), and a leaving group (element or compound capable of leaving in exchange for another group). Acid chlorides act as strong electrophilic species because they contain a carbonyl affixed to a strong, stable leaving group, meaning it will form a stable product following the addition. Due to the nature of the stable leaving group, acid chlorides are comparatively more reactive than other carboxylic acid derivatives.

4-nitrobenzoyl chloride is both resonance stabilized due to the benzyl ring and contains and electron withdrawing NO2 group, both of which lead to this compound being a stronger electrophile 

Criteria for nucleophilic reactions:

Nucleophile (Nu:): Electron rich with full or partial (-). 1-pentanol was a good Nu: due to the presence of Oxygen, electronegative group with full (-) charge.

Electrophile (E+): Electron poor with full or partial (+). Acid Chlorides are a good E+ due to the partial (+) carbon on the carbonyl group.

Leaving group: Conjugate bases of a strong acids that can be easily swapped by another functional group.

Previous investigations indicated that the product was dependent on the nucleophile and the molar ratio of the reagents when acid chlorides were reacted with a wide range of compounds, including phenols, thiols, aminothiols, and thiophenols under various conditions and methods.

Our experiment focused on the esterification reaction of benzoyl chloride (E+) with 1-pentanol (Nu:) in anhydrous conditions based on what earlier studies had done to generate a higher yield on the ester product.

In this investigation, the effects of temperature, solvent, rate of addition of the benzoyl chloride, and molar ratio of reactants on a nucleophilic reaction, the synthesis of an ester from an acid chloride and an alcohol, were observed. It proved difficult to find published research relating to reactions between these specific types of electrophile (acid chlorides) and nucleophile (an alcohol). This investigation intends to expand on current research available on acid chlorides.

Using acid chlorides as a starting material for ester synthesis is expected to result in relatively high yields because acid chlorides are relatively reactive, so reactions with them tend to go further to completion than with other electrophiles such as anhydrides. However, because acid chlorides react so readily, conditions must be anhydrous, and there are relatively few options for solvents that do not react with the acid chloride. Side reactions are difficult to prevent. Understanding the effects of reaction conditions on this method of ester synthesis enables implementing improved methods. 

Nucleophilic reactions happen when an electron rich compound (Nu-) attacks an electrophile (E+) of electron deficient compound. It is used to synthesize many different functional groups (esters, amide, and anhydride). Choosing a good electron source is an important factor of the reaction. Many researchers have used acid chlorides as an E+, due to the highly electronegative O and Cl pulling electron density away from the carbon and creating a positive charge. Previous papers have used alcohols or phenols as the Nu- to produce esters. However, there is limited information about changing the ratio of E+ and Nu- in an experiment while keeping other conditions constant. This study also focused on synthesizing esters with a variety of electron donating groups, electron withdrawing groups, and steric effects on the acid chloride. 

Esters are stable and abundantly found derivatives of carboxylic acids. Esters can be found in several biological molecules and are widely used in industries. To mention some, esters are found in glycerides which are fatty acid esters, and Lactones which contribute to the aroma of fruits and vegetables. Esters can be synthesized using several ways but the use of acid chlorides which are highly reactive derivatives of a carboxylic acid with alcohol; a weak nucleophile is a very effective and fast way to synthesize esters. 4-nitrobenzoyl chloride when treated with an alcohol, pentanol in the presence of base triethylamine produces pentyl 4-nitrobenzoate via Nucleophilic acyl substitution. Resonance along with the net effect of the chlorine atom to withdraw electron density and the presence of a EWG nitro group, renders the carbonyl group extremely electrophilic. This makes the carbonyl carbon susceptible to nucleophilic attacks where the nucleophile replaces the leaving in a reaction known as nucleophilic acyl substitution. Nucleophilic acyl substitution happens in two steps nucleophilic attack by the alcohol pentanol in this case, followed by a formation of a tetrahedral intermediate which leads to the reformation of the carbonyl and expulsion of the leaving group to form an ester. The leaving group, Chloride ion forms HCl and is scavenged by the base, triethylamine in the course of the reaction.

A nucleophilic reaction occurs when an electron-rich compound (Nu) attacks an electron-deficient compound (E+); The Nucleophile donates a pair of electrons to the electron-deficient center of the electrophile, leading to the formation of a new bond. This type of reaction is used to synthesize many different functional groups (Esters, Amides, and Anhydrides) Its large versatility and selectivity are its advantages. However, its reactivity can also lead to side reactions, sensitivity to reaction conditions and slow reaction rates. In previous studies, researchers have used acid chlorides as the E+ because the high electronegativity of Cl- & O- is able to pull electrons away to generate a good E+. And they chose the Alcohol function group as the Nu to synthesize Ester. However, the studies did not compare the ratio of Nu to E+ when synthesizing the Ester, and also did not have a consistent solvent, temperature and time. Therefore, in this study, we focus on finding a good parameters for the nucleophilic reaction and comparing yield of product (Ester) on reactions ran in different ratios of Acid Chlorides to Ester (Nu : E).