SERIOUS ANSWERS ONLY! Explain the damage that can be caused by performing presumptive drug tests as confirmatory tests, making sure to cite one specific example to support your explanation. Proper spelling, grammar, and sentence structure are expected.

Explanation:

The US Food and Drug Administration issued a Premarket Submission and Labeling Recommendations for Drugs of Abuse Screening Tests. Its availability was announced in the Federal Register, Vol. 68, No. 231 on December 2, 2003 and is listed under "Notices." Presumptive testing has found widespread use by employers and public entities. Most people who take a drug test take a presumptive test, cheaper and faster than other methods of testing. However, it is less accurate and can render false results. The FDA recommends for confirmatory testing to be conducted and the placing of a warning label on the presumptive drug test: "This assay provides only a preliminary result. Clinical consideration and professional judgment should be applied to any drug of abuse test result, in evaluating a preliminary positive result. To obtain a confirmed analytical result, a more specific alternate chemical method is needed. Gas chromatography/mass spectrometry (GC/MS) is the recommended confirmatory method."

A drug test is a technical analysis of a biological specimen, for example urine, hair, blood, breath, sweat, and/or oral fluid/saliva—to determine the presence or absence of specified parent drugs or their metabolites. Major applications of drug testing include detection of the presence of performance enhancing steroids in sport, employers and parole/probation officers screening for drugs prohibited by law (such as cannabis, cocaine, methamphetamine, and heroin) and police officers testing for the presence and concentration of alcohol (ethanol) in the blood commonly referred to as BAC (blood alcohol content). BAC tests are typically administered via a breathalyzer while urinalysis is used for the vast majority of drug testing in sports and the workplace. Numerous other methods with varying degrees of accuracy, sensitivity (detection threshold/cutoff), and detection periods exist.

he detection windows depend upon multiple factors: drug class, amount and frequency of use, metabolic rate, body mass, age, overall health, and urine pH. For ease of use, the detection times of metabolites have been incorporated into each parent drug. For example, heroin and cocaine can only be detected for a few hours after use, but their metabolites can be detected for several days in urine. The chart depicts the longer detection times of the metabolites.

Oral fluid or saliva testing results for the most part mimic that of blood. The only exceptions are THC (tetrahydrocannabinol) and benzodiazepines. Oral fluid will likely detect THC from ingestion up to a maximum period of 6–12 hours. This continues to cause difficulty in oral fluid detection of THC and benzodiazepines.[2]

Breath air for the most part mimics blood tests as well. Due to the very low levels of substances in the breath air, liquid chromatography—mass spectrometry has to be used to analyze the sample according to a recent publication wherein 12 analytes were investigated.

Rapid oral fluid products are not approved for use in workplace drug testing programs and are not FDA cleared. Using rapid oral fluid drug tests in the workplace is prohibited in only:[3]

Alcohol6–24 hours[6] Note: Alcohol tests may measure ethyl glucuronide, which can stay in urine for up to 80 hoursup to 90 days[7]12 to 24 hours

Amphetamines (except methamphetamine)1 to 3 days[8]up to 90 days12 hours

Methamphetamine3 to 5 days[9]up to 90 days1 to 3 days[9]

MDMA (Ecstasy)3 to 4 daysup to 90 days3 to 4 days

Barbiturates (except phenobarbital)1 dayup to 90 days1 to 2 days

Phenobarbital2 to 3 weeks[10]up to 90 days4 to 7 days

BenzodiazepinesTherapeutic use: up to 7 days. Chronic use (over one year): 4 to 6 weeksup to 90 days6 to 48 hours

CannabisPassive inhalation: up to 22 minutes** Infrequent users: 7-10 Days; Heavy users:30 to 100 days;[11][12][13]up to 90 days[11]2 to 3 days in blood, up to 2 weeks in blood of heavy users[11] However, it depends on whether actual THC or THC metabolites are being tested for, the latter having a much longer detection time than the former. THC (found in marijuana) may only be detectable in saliva/oral fluid for 2 to 24 hours in most cases, though in rare cases has been detected up to 28 days after consumption.[14]

Cocaine2 to 5 days (with exceptions for heavy users who can test positive up to 4/6 weeks, and individuals with certain kidney disorders)up to 90 days2-10 days, heavy users or individuals with previous substance abuse 6/8 weeks

Codeine2 to 3 daysup to 90 days1 to 4 days

Cotinine (a breakdown product of nicotine)2 to 4 daysup to 90 days2 to 4 days

Morphine2 to 4 daysup to 90 days1 to 3 days

Tricyclic antidepressants (TCA's)7 to 10 daysUndetectable[15]Detectable but dose relationship not established.

LSD2–24 hoursup to 4 days[citation needed]2 to 4 days

Methadone7 to 10 daysup to 90 days24 hours

Steroids3 to 30 days  

PCP3 to 7 days for single use; up to 30 days in chronic users[16]up to 90 days1 to 3 days[16]

when 25.0 ml of 0.700 mol/l naoh was mixed in a calorimeter with 25.0 ml of 0.700 mol/l hcl, both initially at 20.0 °c, the temperature increased to 22.1 °c. the heat capacity of the calorimeter is 279 j/°c.

the equation for the reaction is:

naoh + hcl → nacl + h₂o

moles of hcl = 0.0250 l hcl ×

0.700

mol hcl

1 l hcl = 0.0175 mol hcl

volume of solution = (25.0 + 25.0) ml = 50.0 ml

mass of solution = 50.0 ml soln ×

1.00

ml soln

= 50.0 g soln

δt=t2-t1

= (22.1 – 20.0) °c = 2.1 °c

the heats involved are

heat from neutralization + heat to warm solution + heat to warm calorimeter = 0

q1+q2+q3=0

nδh+mcδt+cδt=0

0.0175 mol ×

δh

+ 50.0 g × 4.184 j·g⁻¹°c⁻¹ × 2.1 °c + 279 j°c⁻¹ × 2.1 °c = 0

0.0175 mol ×

δh

+ 439.32 j + 585.9 j = 0

0.0175 mol ×

δh

= -1025.22 j

δh=1025.22j0.0175 mol= -58 600 j/mol = -58.6 kj/mol