This is possible, but a bit indirect.
You have to subscribe to AnyOfferChangedNotification through the Subscription API. Then you can process messages in your Amazon Simple Queue Service (SQS) queue. This messages will contain SellerID´s and you can identify amazon.
Notifications will look like:
<Notification>
<NotificationMetaData>
<NotificationType>AnyOfferChanged</NotificationType>
<PayloadVersion>1.0</PayloadVersion>
<UniqueId>c027f13372c522</UniqueId>
<PublishTime>2015-11-03T16:24:13.907Z</PublishTime>
<SellerId>1337</SellerId>
<MarketplaceId>A1PA6795UKMFR9</MarketplaceId>
</NotificationMetaData>
<NotificationPayload>
<AnyOfferChangedNotification>
<OfferChangeTrigger>
<MarketplaceId>A1PA6795UKMFR9</MarketplaceId>
<ASIN>B00FQ8AVHS</ASIN>
<ItemCondition>new</ItemCondition>
<TimeOfOfferChange>2015-11-03T16:24:13.664Z</TimeOfOfferChange>
</OfferChangeTrigger>
<Summary>
<NumberOfOffers>
<OfferCount condition="new" fulfillmentChannel="Amazon">2</OfferCount>
<OfferCount condition="new" fulfillmentChannel="Merchant">14</OfferCount>
<OfferCount condition="used" fulfillmentChannel="Amazon">2</OfferCount>
</NumberOfOffers>
<LowestPrices>
<LowestPrice condition="new" fulfillmentChannel="Amazon">
<LandedPrice>
<Amount>88.02</Amount>
<CurrencyCode>EUR</CurrencyCode>
</LandedPrice>
<ListingPrice>
<Amount>88.02</Amount>
<CurrencyCode>EUR</CurrencyCode>
</ListingPrice>
<Shipping>
<Amount>0.00</Amount>
<CurrencyCode>EUR</CurrencyCode>
</Shipping>
</LowestPrice>
<LowestPrice condition="new" fulfillmentChannel="Merchant">
<LandedPrice>
<Amount>92.50</Amount>
<CurrencyCode>EUR</CurrencyCode>
</LandedPrice>
<ListingPrice>
<Amount>88.00</Amount>
<CurrencyCode>EUR</CurrencyCode>
</ListingPrice>
<Shipping>
<Amount>4.50</Amount>
<CurrencyCode>EUR</CurrencyCode>
</Shipping>
</LowestPrice>
<LowestPrice condition="used" fulfillmentChannel="Amazon">
<LandedPrice>
<Amount>79.26</Amount>
<CurrencyCode>EUR</CurrencyCode>
</LandedPrice>
<ListingPrice>
<Amount>79.26</Amount>
<CurrencyCode>EUR</CurrencyCode>
</ListingPrice>
<Shipping>
<Amount>0.00</Amount>
<CurrencyCode>EUR</CurrencyCode>
</Shipping>
</LowestPrice>
</LowestPrices>
<BuyBoxPrices>
<BuyBoxPrice condition="new">
<LandedPrice>
<Amount>88.08</Amount>
<CurrencyCode>EUR</CurrencyCode>
</LandedPrice>
<ListingPrice>
<Amount>88.08</Amount>
<CurrencyCode>EUR</CurrencyCode>
</ListingPrice>
<Shipping>
<Amount>0.00</Amount>
<CurrencyCode>EUR</CurrencyCode>
</Shipping>
</BuyBoxPrice>
</BuyBoxPrices>
<ListPrice>
<Amount>197.47</Amount>
<CurrencyCode>EUR</CurrencyCode>
</ListPrice>
<SuggestedLowerPricePlusShipping>
<Amount>88.00</Amount>
<CurrencyCode>EUR</CurrencyCode>
</SuggestedLowerPricePlusShipping>
<SalesRankings>
<SalesRank>
<ProductCategoryId>automotive_display_on_website</ProductCategoryId>
<Rank>122</Rank>
</SalesRank>
<SalesRank>
<ProductCategoryId>4958715031</ProductCategoryId>
<Rank>11</Rank>
</SalesRank>
</SalesRankings>
<BuyBoxEligibleOffers>
<OfferCount condition="new" fulfillmentChannel="Amazon">2</OfferCount>
<OfferCount condition="new" fulfillmentChannel="Merchant">13</OfferCount>
<OfferCount condition="used" fulfillmentChannel="Amazon">2</OfferCount>
</BuyBoxEligibleOffers>
</Summary>
<Offers>
<Offer>
<SellerId>A3TZZ7DOC6G9UH</SellerId>
<SubCondition>new</SubCondition>
<SellerFeedbackRating>
<SellerPositiveFeedbackRating>99</SellerPositiveFeedbackRating>
<FeedbackCount>18539</FeedbackCount>
</SellerFeedbackRating>
<ShippingTime minimumHours="0" maximumHours="0" availabilityType="NOW"/>
<ListingPrice>
<Amount>88.02</Amount>
<CurrencyCode>EUR</CurrencyCode>
</ListingPrice>
<Shipping>
<Amount>0.00</Amount>
<CurrencyCode>EUR</CurrencyCode>
</Shipping>
<IsFulfilledByAmazon>true</IsFulfilledByAmazon>
<IsBuyBoxWinner>false</IsBuyBoxWinner>
<IsFeaturedMerchant>true</IsFeaturedMerchant>
<ShipsDomestically>true</ShipsDomestically>
</Offer>
<!-- more offers here -->
</Offers>
</AnyOfferChangedNotification>
</NotificationPayload>
</Notification>
In this example I cutted off other Offers to make it a bit shorter. As you can see the value of Notification.NotificationPayload.AnyOfferChangedNotification.Offers.Offer.SellerId
is A3TZZ7DOC6G9UH. Amazon has its own unique SellerId for their seller accounts.
If you has set up such a system and keep track of this information for all your products you will know wich one is sold by amazon. I am doing this for a big amount of products and it works fine.