To most onlookers, the two rows of white, nondescript boxes lined up 在车道上似乎没什么意义.
But to the energetic rescue dog whose ears perk at an impossibly cute 角度，这些盒子不能再多了 重要的. 他们的意思是该去上班了.
As Laurie Witucki, professor of chemistry, sets up the boxes, her dog Rue sits in the garage, a purposeful gaze affixed on the containers as 她等待着下一步. 然后，维图斯基把鲁带到包厢前.
Upon hearing the search command “Find it,” Rue quickly sniffs at 然后用爪子轻拍其中一只. “好女孩!维图斯基喊道. 然后Rue继续前进，寻找另一个盒子.
Rue has found the boxes containing oils with specific smells, such as 桦木. 这项活动是一项正在兴起的名为“犬嗅”的运动的一部分 work, or nosework, modeled after the 培训 for dogs used in law 执法部门或军队. 参加这项运动的狗是经过训练的 to locate essential oils hidden in containers or vehicles, in indoor 户外环境.
That hobby also led to research by Witucki on the essential oils used for competitions and 培训, showing how a wide range of impurities within the oils, depending on the vendor, can affect how the dogs 表演，因为气味会迷惑它们.
Witucki knows scent is complex and dogs smell all of the components in a given substance, so she 说 the chemist in her had a theory for 培训. “我在看狗狗通过一个 科学家的眼睛，”维图斯基说. “有没有一种共同的化学成分 在我可以训练的所有精油中?”
结果是:“我们没有找到神奇的分子. 我们发现了很多 不同的杂质.”
“狗分别闻面包，酱汁， the cheese and pepperoni. I was 培训 him on a cheese pizza, asking him to find a piece of pepperoni.”
德莱尼约翰逊
Witucki and fellow researchers 德莱尼约翰逊 and David Mugica-Canos used gas chromatography-mass spectrometry to separate and identify the components of certain oils from numerous commercial suppliers.
They compared those results to substances they freshly distilled by 蒸汽. They analyzed six oils used extensively in competition: 桦木, 八角，丁香，没药，香根草和柏树.
The range of impurity levels was a revelation, Witucki 说, adding myrrh is the most difficult odor to train with because the commercial oil sometimes contained 98 percent chemical solvent impurities.
The results also led to a resignation on Witucki’s part: She and other handlers in the scent work sport need to train on multiple commercial oils because they never know which one a judge will choose. Training on pure oils from a single source is not the best option due 他们发现了变化.
Johnson, a student researcher studying chemistry, was a high school student participating in the competitions when she first met Witucki. Once she started attending Grand Valley, Johnson was thrilled when Witucki approached her with a chance to conduct research on the oils, 她花了好几个学期来做这件事.
Myrrh became a problem for Johnson when one of her dogs, a constant winner, suddenly lost skills when trying to find the essential oil. She then learned through the research how impurities affected the scent.
“The analogy I use is that when you walk into a pizza place, you 闻一闻整个披萨. 狗分别闻面包，酱汁， 奶酪和意大利辣香肠，”约翰逊说. “我在训练他 cheese pizza and taking him to a show, asking him to find a piece of pepperoni.”
Johnson, who competes with three dogs — two Dutch shepherds and a rat terrier — 说 it was helpful for her to know the project from the 在她从化学反应中了解这项运动之前，她对这项运动的看法 的角度来看. 她能够把新的学术知识应用起来 它变成了她已经理解的东西.
Witucki has plans to continue the research by testing dogs competing at a high level in a double blind study, setting out a low-quality oil and one of the discovered chemical impurities to see which one the 犬科动物互相攻击.
While this continued research is providing important data for a growing and popular sport, it has additional benefits, Witucki 说. Students in her research lab and chemistry classes are learning about 分析这些物质的过程. Also, as people使用 精油，从芳香疗法到饮食 supplements, it’s helpful to know that oils have different levels of 纯洁，不会变质.
Witucki 说 the research has also helped her foresee blending her scientific background with the sniffing prowess of dogs to potentially 为人类解锁更多利益.
“作为一名科学家，我怎样才能帮助它们成为更好的探测器?“Witucki 说. “我认为这项研究是一个基石. 一旦我明白 chemicals in these oils and what dogs detect, are there molecules that they can also be trained on for the detection of things like cancer?”
For now, Witucki is enjoying finding out more about oils for a sport 她爱的东西. 而鲁，被列为金毛猎犬/边境牧羊犬 mix but described by Witucki as “100 percent all-American adorable howler” is one of the sport’s top dogs in the nation, Witucki also competes with her 10-year-old golden retriever, 格雷西, who is retired 来自敏捷竞赛.
In fact, the sport is a beneficial, low-impact activity for those with a senior dog, 说 Witucki, who also believes it strengthens the 人类和狗之间的纽带.
“任何一只狗都能做到，”维图斯基说. “这是一项容易接受的运动和狗 喜欢有任务. 这让他们在密歇根的冬天有事可做.”
